fsc2: 6.7 Digitizer Functions

6.7 Digitizer Functions

Modules for the following digitizing oscilloscopes currently exist:

tds520: Tektronix TDS520
tds520a: Tektronix TDS520A
tds520c: Tektronix TDS520C
tds540: Tektronix TDS540
tds744a: Tektronix TDS744A
tds754a: Tektronix TDS754A
lecroy9400: LeCroy 9400 (with the WP01 Waveform Processing option)
lecroy9410: LeCroy 9410
lecroy9420: LeCroy 9420
lecroy9424: LeCroy 9424
lecroy9424e: LeCroy 9424e
lecroy9450: LeCroy 9450
lecroy93xx: LeCroy 9304, 9304A, 9304AM, 9304AL, 9304C, 9304CM, 9304CL, 9310, 9310A, 9310AM, 9310AL, 9310C, 9310CM, 9310CL, 9314, 9314A, 9314AM, 9314AL, 9314C, 9314CM, 9314CL, 9350, 9350A, 9350AM, 9350AL, 9350C, 9350CM, 9350CL, 9354, 9354A, 9354AM, 9354AL, 9354C, 9354CM, 9354CL, 9354TM, 9354CTM,
lecroy_wr, lecroy_wr_l, lecroy_wr_s: LeCroy Waverunner, Waverunner-2 and X-Stream series controlled via GPIB, LAN or serial port (models LT224, LT322, LT342, LT342L, LT344, LT344L, LT364, LT364L,
LT262, LT264, LT264M, LT354M, LT354ML, LT372, LT372M, LT374, LT374M, LT374L, LT584, LT584M and LT584L, 44Xi, 44MXi, 62Xi, 64Xi, 64MXi, 104Xi, 104MXi, 204Xi, 204MXi)
lecroy_ws, lecroy_ws_g: LeCroy WaveSurfer series controlled via LAN or GPIB (models 422, 424, 432, 434, 452 and 454)
Rohde&Schwarz RTO series: (Models RTO1002, RTO1004, RTO1012, RTO1014, RTO1022, RTO1024, RTO1044)

To use a module in an experiment put its name into the DEVICES section of the EDL script.

In some cases there exists a module for each of the supported models (Textronix and LeCroy 94xx series) while in all others, due to the huge number of different models in a series, there's only a single module that, depending on the settings in the configuration file for the module, gets taylored for one of the models in the series.

When specifying digitizer channels or trigger inputs you should use only the following symbolic names (internally these symbolic names get replaced by integer numbers, so the functions expecting channel numbers accept integers, but the relation between a channel specified by its symbolic name and the corresponding number isn't trivial). Note that Lecroy X-Stream oscilloscopes aren't specially mentioned since the same module as for the Waverunner model is used.

`CH1': First digitizer channel (all models)
`CH2': Second digitizer channel (all models)
`CH3': Third digitizer channel (Tektronix TDS540, TDS744A, TDS754A, LeCroy 9424, LeCroy 9424E, some models of the 93xx, Waverunner, WaveSurfer and Rohde&Schwarz RTO series)
`CH4': Fourth digitizer channel (Tektronix TDS540, TDS744A, TDS754A, LeCroy 9424, LeCroy 9424E, some models of the 93xx, Waverunner, WaveSurfer and Rohde&Schwarz RTO series)
`MATH1': First mathematic function channel (all Tektronix and R&S RTO digitizers)
`MATH2': Second mathematic function channel (all Tektronix and R&S RTO digitizers)
`MATH3': Third mathematic function channel (all Tektronix and R&S RTO digitizers)
`MATH4': Fourth mathematic function channel (R&S RTO digitizers)
`REF1': First reference channel (all Tektronix digitizers)
`REF2': Second reference channel (all Tektronix digitizers)
`REF3': Third reference channel (all Tektronix digitizers)
`REF4': Fourth reference channel (all Tektronix digitizers)
`AUX': Auxiliary channel (Tektronix TDS540, TDS744A, TDS754A)
`AUX1': First auxiliary channel (Tektronix TDS520, TDS520A, TDS520C)
`AUX2': Second auxiliary channel (Tektronix TDS520, TDS520A, TDS520C)
`EXP_A': First expansion channel (LeCroy 94xx)
`EXB_B': Second expansion channel (LeCroy 94xx)
`MEM_C': Memory channel C (LeCroy 94xx)
`MEM_D': Memory channel D (LeCroy 94xx)
`M1': Memory channel 1 (LeCroy 93xx, Waverunner, WaveSurfer)
`M2': Memory channel 2 (LeCroy 93xx, Waverunner, WaveSurfer)
`M3': Memory channel 3 (LeCroy 93xx, Waverunner, WaveSurfer)
`M4': Memory channel 4 (LeCroy 93xx, Waverunner, WaveSurfer)
`MATH': Math (function) channel (LeCroy WaveSurfer)
`FUNC_E': First function (averaging) channel (LeCroy 94xx)
`FUNC_F': Second function (averaging) channel (LeCroy 94xx) 9450)
`TRACE_A': First function (averaging) channel (LeCroy 93xx, Waverunner, WaveSurfer)
`TRACE_B': Second function (averaging) channel (LeCroy 93xx, Waverunner, WaveSurfer)
`TRACE_C': Third function (averaging) channel (LeCroy 93xx, Waverunner, WaveSurfer)
`TRACE_D': Fourth function (averaging) channel (LeCroy 93xx, Waverunner, WaveSurfer)
`LINE': Line In for trigger (all models)
`EXT': External trigger input (LeCroy 93xx, 94xx (except 9424), WaveSurfer, Waverunner) and R&S RTO series
`EXT10': External amplified trigger input (LeCroy 93xx, 94xx (except 9424 and 9424E), WaveSurfer, Waverunner)

List of digitizer functions:

`digitizer_name()'
`digitizer_timebase()'
`digitizer_timebase_limits()'
`digitizer_timebase_const_resolution_limits()'
`digitizer_interleave_mode()'
`digitizer_time_per_point()'
`digitizer_time_per_point_limits()'
`digitizer_sensitivity()'
`digitizer_offset()'
`digitizer_coupling()'
`digitizer_bandwidth_limiter()'
`digitizer_ext_channel_filter()'
`digitizer_channel_position()'
`digitizer_num_averages()'
`digitizer_num_segments()'
`digitizer_max_num_segments()'
`digitizer_averaging()'
`digitizer_acquisition_mode()'
`digitizer_trigger_channel()'
`digitizer_trigger_level()'
`digitizer_trigger_slope()'
`digitizer_trigger_coupling()'
`digitizer_trigger_mode()'
`digitizer_trigger_position()'
`digitizer_trigger_delay()'
`digitizer_record_length()'
`digitizer_record_length_limits()'
`digitizer_memory_size()'
`digitizer_define_window()'
`digitizer_change_window()'
`digitizer_window_position()'
`digitizer_window_width()'
`digitizer_window_limits()'
`digitizer_check_window()'
`digitizer_display_channel()'
`digitizer_channel_state()'
`digitizer_start_acquisition()'
`digitizer_run()'
`digitizer_stop()'
`digitizer_available_data()'
`digitizer_get_curve()'
`digitizer_get_curve_fast()'
`digitizer_get_area()'
`digitizer_get_area_fast()'
`digitizer_get_amplitude()'
`digitizer_get_amplitude_fast()'
`digitizer_get_segments()'
`digitizer_get_segment_area()'
`digitizer_get_segment_amplitude()'
`digitizer_available_segments()'
`digitizer_run()'
`digitizer_copy_curve()'
`digitizer_math_function()'
`digitizer_lock_keyboard()'
`digitizer_display_enable()'
`digitizer_trigger_out_pulse_state()'
`digitizer_trigger_out_pulse_length()'
`digitizer_trigger_out_pulse_polarity()'
`digitizer_trigger_out_pulse_delay()'
`digitizer_trigger_out_pulse_delay_limits()'

Descriptions of digitizer functions:

`digitizer_name()'

Returns a string with the name of the digitizer being used.

`digitizer_timebase()'

The function queries (if called with no argument) or sets (if called with an argument) the timebase setting of the oscilloscope. The possible timebases depend on the model, please check the manual.

For all LeCroy digitizers (except the 9400) interleaved sample (RIS) mode will be automatically switched on if the selected timebase requires it (see the manuals at which timebase settings RIS or single shot mode is only possible). Changing the timebase for these digitizers may thus also lead to a change in the number of points of a trace.

Please note that trying to change the timebase may lead to the program getting aborted if the new timebase setting isn't compatible with a previously set trigger delay (i.e. if the trigger delay requested previously isn't possible with the new setting of the timebase).

For the R&S RTO series the time resolution (point per time) is kept unmodified as far as possible (given that enough memory is available), to keep the record length constant a following call of digitizer_time_per_point() is necessary. The trigger delay changes automatically if the previous setting isn't compatible with the new timebase.

The function can be called in the EXPERIMENT section only.

`digitizer_timebase_limits()'

This function is only supported for the R&S RTO series. It takes no arguments and returns an array with two elements with the shortest and longest timebase that can be set under the current circumstances.

The function can be called in the EXPERIMENT section only.

`digitizer_timebase_const_resolution_limits()'

This function is only supported for the R&S RTO series. This function is only supported for the R&S RTO series. It takes no arguments and returns an array with two elements with the shortest and longest timebase that can be set under the current circumstances without resulting in an automatic change of the time resolution.

The function can be called in the EXPERIMENT section only.

`digitizer_time_per_point()'

The function (to be called in the EXPERIMENT section only) returns the time difference (in seconds) between two data points measured by the digitizer.

For the R&S RTO series this function also can be called to request a certain time resolution (highest possible resolution is 100 ps. This will change the record length.

`digitizer_time_per_point_limits()'

This function is only supported for the R&S RTO series. It takes no arguments and returns an array with two values, the shortest and the longest time resolution possible under current circumstances (timebase, memort available etc.).

The function can be called in the EXPERIMENT section only.

`digitizer_interleave_mode()'

This function is only available for the LeCroy digitizers (except the 9400). It allows to switch between interleaved (RIS) and single shot (SS) mode, given that setting the mode is compatible with the currently selected timebase. Please note that by changing the timebase interleaved mode may get switched on or off automatically.

If called without an argument the function returns the requested mode (independent of the mode the digitizer is currently in due to the timebase setting, i.e. it reflects the prefered setting, not the actual setting, which might be different due to requeirements from the current timebase setting), 1 when interleaved (RIS) mode is requested, and 0 for single shot (SS) mode.

`digitizer_sensitivity()'

The function queries (if called with just one argument) or sets (if called with two arguments) the sensitivity setting of one of the channels of the oscilloscope. The channel can be any of the digitizing channels of the oscilloscope. For the LeCroy Waverunner series in queries also one of the trace channels can be used if it has been set for averaging (see digitizer_averaging()). For the R&S RTO series, also any of the math channels can be used.

If a second argument is given this is taken to be the new sensitivity setting (in Volts per division). If the sensitivity value passed to the function is not one of the available settings the nearest allowed value is used instead. Please note that for some of the oscilloscopes the range of admissible sensitivity settings depends on the input impedance - unfortunately this can only be checked for when the experiment has already been started. Requesting an impossible setting may either result in the EDL script getting aborted or in an automatic change of the input coupling (always accompanied by a warning message).

If no second argument is given the current sensitivity setting for the channel is returned.

The function can be called in query mode (i.e. without a second argument) only in the EXPERIMENT section.

`digitizer_offset()'

The function queries (if called with just one argument) or sets (if called with two arguments) the offset setting of one of the digitizing channels of the oscilloscope. Currently this function only exists for the LeCroy osccilloscopes (except 9400 and the R&S RTO series (which also allows setting an offset for the math channels).

If a second argument is given this is taken to be the new offset setting (in Volts). If no second argument is given the current offset setting for the channel is returned.

The allowed range for theo ffset normally depends on the sensitivity setting for the channel. Please refer to the device manual.

The function can be called in query mode (i.e. without a second argument) only in the EXPERIMENT section.

`digitizer_coupling()'

The function queries (if called with just one argument) or sets (if called with two arguments) the input coupling of one of some of the channels of the oscilloscope, all digizitizing channels and, for the R&S RTO series, the external trigger input channel. Currently this function only exists for the Tektronix, LeCroy and Rohde&Schwarz oscilloscopes.

If a second argument is given this is taken to be the new input coupling setting, which has to b specified a string or an integer number, where "A1M" or 0 stands for AC with 1 MOhm, "D1M" or 1 for DC with 1 MOhm, "D50" for DC with 50 Ohm and "GND" or 3 for Ground. For the Tektronix oscilloscopes there's a further possibility, "A50" or 4 for AC with 50 Ohm. If no second argument is given the current setting for the channel is returned as an integer number.

Please note that for some of the oscilloscopes the range of input sensitivity settings may depend on the input impedance and requesting an invalid combination may result in aborting the EDL script or in an automatic change of the sensitivity setting.

The function can be called in query mode (i.e. without a second argument) only in the EXPERIMENT section.

`digitizer_bandwidth_limiter()'

This function allows to set or query the bandwidth limiter(s) of the oscilloscopes. For the oscilloscopes of the Lecroy93xx and Lecroy94xx series the bandwidth can only be set or queried for all channels at once, while for the other supported oscilloscopes the bandwidth limit can be set for individual channels. Thus for the Lecroy93xx and Lecroy94xx series oscilloscopes the function takes either no (in query mode) or a single argument (if the bandwidth is to be set), while for all others the function expects one or two arguments, the first one always being the digitizing channel to be set up.

For the oscilloscopes of the Lecroy93xx and Lecroy94xx series the function queries (if called with no argument) or sets (if called with an arguments) if the bandwidth limiter (30 MHz for the 9400) and 80 MHz for all others) is switched on or off. If an argument is given and it is a non-zero number or the string "ON" the bandwidth limiter is switched on, if the argument is zero or the string "OFF" the bandwidth limiter is switched off. If called without an argument the function returns 1 if the bandwidth limiter is on, 0 if it's off.

For all but one of the supported models of the LeCroy Waverunner series three possible settings exist. It can be switched off (i.e. for using the full bandwidth) by calling the function with a string argument of "OFF" (or an integer argument of 0) to achieve the highst model-dependent bandwidth (see specifications). It can be set to 200 MHz by calling the function with the string "200MHZ" (or the value 2). Finally by calling it with the string "ON" (or an integer argument of 1) for bandwidth can be restricted to 25 MHz for the Waverunner models LT322, LT342(L), LT262(ML) and LT372(L)) and to 20 MHz for the Waverunner-2 models LT224, LT344(L), LT364(L), LT264(M/ML), LT354(M/ML), LT374(M/L) and LT584(M/L) and all Xi models. The only exception is the Waverunner model LT322 were the maximum bandwidth is 200 MHz, thus switching the bandwidth limiter off and setting it to 200 MHz has the same effect.

For the LeCroy WaveSurfer with the models 422 and 424 only "OFF" and "ON" can be set, while with the other models also "200MHZ" can be set (the maximum bandwidth of the 422 and 424 models is 200 MHz, so this limit is already reached when the bandwidth limiter is set to "OFF".

For all Tektronix oscilloscopes there exist at least three possible settings, the string "OFF" or the integer value 0 for full bandwidth, "20MHZ" or 1 and "100MHZ" or 2. The models TDS744A and TDS754A support a further setting, "250MHZ" or 3.

For all models of the R&S RTO series 4 possible settings exist: "OFF" (or 0) for full bandwidth, "20MHz" (or 1), "200MHz" (or 2) And "800MHz" (or 4) Though note that this setting is equivalent to "OFF" for the models RTO1002 and RTO1004. Also, the 800 MHz setting is only possible with the DC 50 Ohm input coupling setting.

The function can be called only in the EXPERIMENT section.

`digitizer_ext_channel_filter()'

This function is only available for the R&S RTO series. The device allows to set a low- or high-pass filter (with anumber of different cut-off frequencies) for the external trigger input channel. This function allows to query or set that filter. The possible arguments (or return values as integers are)

`"Off" or 0': Filter switched off
`"Low_Pass_5kHz" or 1': Low-pass filter with 5 kHz cut-off frequency
`"Low_Pass_50kHz" or 2': Low-pass filter with 50 kHz cut-off frequency
`"Low_Pass_50MHz" or 3': Low-pass filter with 50 MHz cut-off frequency
`"High_Pass_5kHz" or 4': High-pass filter with 5 kHz cut-off frequency
`"High_Pass_50kHz" or 5': High-pass filter with 50 kHz cut-off frequency
`"High_Pass_50MHz" or 6': High-pass filter with 50 MHz cut-off frequency

`digitizer_channel_position()'

This function is only available for the R&S RTO series. The displayed waveform of a channel can be moved vertically between -5 and 5 dib. This function allows to query or set the position. It expects at least one argument, either a digitizing or a math channel. Without another argument the current position is returned. When called with a second argument this will be used as the new vertical position.

`digitizer_num_averages()'

For the Tektronix digitizers the function queries (if called with no argument) or sets (if called with an argument) the number of averages done by the oscilloscope. If the number of averages is passed to the function it must be at least 1 (which will switch the oscilloscope into SAMPLE mode). If the argument is larger than the maximum number of averages the maximum available number of averages is used instead.

For the LeCroy oscilloscopes this function can only be used in query mode and returns the number of averages that has been set in a previous call of digitizer_averaging(). It needs exactly one argument, the the channel used to do the averaging, i.e. either FUNC_E or FUNC_F for the LeCroy 9400, 9410, 9420, 9424, 9424E, 9450 and TRACE_A, TRACE_B, TRACE_C or TRACE_D for the Waverunner.

For the R&S RTO series the function can be used to query or set the number of averages sampled when doing a easurrement in Averaged acquisition mode). Possible values are between 1 and 16777215.

Please note:: Anton Savitzky noticed that there seems to be firmware bug in the Tektronix digitzers from the 500 series (i.e. TDS520, TDS520A, TDS520C and TDS540). For numbers of averages above about 16 only half of the number of averages seem to be taken by the device it has been instructed to do. It's hard to say which is the exact number of averages this bug starts at because it only shows up in the signal-to-noise ratio being worse by a factor of the square root of 2 than is to be expected.

`digitizer_num_segments()'

This function only exists for the R&S RTO series. It queries or sets the number of waveforms measured during acquisition in "Segmented acquisition mode (also called "Ultra Segmentation"). The lower limit this can be set to is 1, the upper limit depends on a lot of circumstances, use digitizer_max_num_segments() to find out what ot is.

`digitizer_max_num_segments()'

This function only exists for the R&S RTO series. It takes no arguments and returns the maximum number of segments that can be mesured under the current circumstances in acquisition mode (also called "Ultra Segmentation")

`digitizer_averaging()'

This function only exists for the LeCroy oscilloscopes and must be used to set up averaging. It expects at least three arguments. The first argument is the channel to be used to do the averaging, i.e.

`LeCroy 9400'
`LeCroy 9410'
`LeCroy 9420'
`LeCroy 9424'
`LeCroy 9424E'
`LeCroy 9450': FUNC_E or FUNC_F
`LeCroy Waverunner': TRACE_A, TRACE_B, TRACE_C or TRACE_D
`LeCroy WaveSurfer': CH1, CH2, CH3 or CH4, MATH

The second is the source channel to be averaged, i.e.

`LeCroy 9400'
`LeCroy 9410'
`LeCroy 9420'
`LeCroy 9450'
`LeCroy Waverunner (LT322, LT342(L), LT262(ML), LT372(L))'
`LeCroy WaveSurfer (422, 432, 452)': CH1 or CH2
`LeCroy 9424'
`LeCroy 9424E'
`LeCroy Waverunner (LT224, LT344(L), LT364(L), LT264(M/ML), LT354(M/ML), LT374(M/L), LT584(M/L))'
`LeCroy WaveSurfer (424, 434, 454)': CH1, CH2, CH3 or CH4

Alternatively, for all digitizers except the LeCroy 9400 the second (and in this case final) argument can be the string "OFF" to switch of averaging for the channel. Normally, this won't be necessary unless you want to fetch a curve acquired in SINGLE trigger mode.

The LeCroy WaveSurfer line of oscilloscopes is somewhat special in that it allows the "normal" channels to be used for (continuous) averaging. I.e. the first argument can be one of the measurement channels and the second argument thn must be the same channel. In this case continuous averaging (in contrast to summed averaging as it's done via the MATH channel) using no MATH channel is done. Please note that when you do continuous averaging with a measurement channel this channel can't be used as the source channe for summed averaging via the MATH channel anymore.

Normally, at the start of an acquisition, the trigger mode gets changed to NORM (or AUTO, if you have set the trigger mode to this). Only in these trigger modes averaging can be done. Only when no averaging setup has been done (or all previously done setups have been deleted by using the "OFF" instead of a source channel) it is possible to start an acquisition in SINGLE trigger mode.

The third required argument is the number of averages. For the LeCroy 9400 this has to be either 1, 2 or 5, multiplied by 10, 100, 1,000, 10,000 etc. up to 1,000,000 (if a number not fitting this scheme is passed to the function the nearest allowed number is used instead).

For the LeCroy 9410, 9420, 9424, 9424E and 9450, 9450 this can be an arbitrary number between 1 and 1,000 (or 1,000,000 if the device is fitted with the WP01 Waveform Processing option).

For the LeCroy Waverunner this also can be an arbitrary number with an upper limit of 4,000 (or 1,000,000 if it is fitted with the WaveAnalyzer option).

Finally, for the LeCroy WaveSurfer the number of averages can be set to a number with an upper limit of 1,000,000. If the number of averages for continuous averaging of a non-MATH channel is set to 1 this is treated as another way of switching off averaging.

For the LeCroy 9400 two more optionals argument can be passed to the function. The first one is either an integer number, with a non-zero value representing truth and 0 false, or a string, either "ON" or "OFF", that determines if overflow rejection is switched on or off (if switched on all traces that overflowed the ADC range will be rejected automatically). The second one is the number of points that get included into the average. Usually it doesn't make too much sense to set this value because the program will make sure that at least as many points of a curve as can be read from the digitizer are included into the averaging. If the value is set only as many points as have been set will be returned by a digitizer_get_curve() command.

`digitizer_acquisition_mode()'

This function only exists for the R&S RTO series. These devices have three "qcquisition modes". You can either just measure a single waveform, measure and average a number of waveforms or measure a consecutive set of single waveforms, which is called "Ultra Segmentation" (in this mode a much faster repetition frequency is possible and data don't need to be downloaded in between since all waveforms are stored on the device). This function can be used to query or set this acquisition mode. Possible values are the string "Normal" (or the integer 0), "Averaged" (or 1) and "Segmented" (or 2).

`digitizer_trigger_channel()'

The function queries or sets the channel of the digitizing oscilloscope to be used as trigger input. Possible arguments or return values are, depending on the type of the oscilloscope (return values are always numeric!):

`TDS520'

`TDS520A'

`TDS520C'

CH1 or CH2
AUX1, AUX2 or LINE (can be abbreviated to LIN)

`TDS540'

`TDS744A'

`TDS754A'

CH1, CH2, CH3 or CH4
AUX or LINE (can be abbreviated to LIN)

`LeCroy 9400'

`LeCroy 9410'

`LeCroy 9420'

`LeCroy 9424E'

`LeCroy 9450'

`LeCroy Waverunner (LT322, LT342(L), LT262(ML), LT372(L))'

`LeCroy WaveSurfer (422, 432, 452)'

CH1 or CH2
EXT, EXT10 or LINE (can be abbreviated to LIN)

`LeCroy Waverunner (LT224, LT344(L), LT364(L), LT264(M/ML), LT354(M/ML), LT374(M/L), LT584(M/L))'

`LeCroy WaveSurfer (424, 434, 454)'

CH1, CH2, CH3 or CH4
EXT, EXT10 or LINE (can be abbreviated to LIN)

`LeCroy 9424'

CH1, CH2 or CH4
LINE (can be abbreviated to LIN)

`LeCroy 9424E'

CH1, CH2
EXT or LINE (can be abbreviated to LIN)

`R&S RTO1002'

`R&S RTO1012'

`R&S RTO1022'

CH1, CH2
EXT

`R&S RTO1004'

`R&S RTO1014'

`R&S RTO1024'

`R&S RTO1044'

CH1, CH2, CH3, CH4
EXT

`digitizer_trigger_level()'

Function for setting or quering the trigger level of one of the trigger channels of the LeCroy 9400, 9410, 9420, 9424, 9424E, 9450, Waverunner and R&S RTO series digitizers. For all digitizers except the LeCroy 9400 it expects at least a single argument, the trigger channel, see the channels listed for the function digitizer_trigger_channel(), for obvious reasons excluding the LINE channel. If called with no further argument the current setting for the trigger level of this channel (or the general level setting in case of the LeCroy 9400) is returned. If called with a second argument it must be the trigger level (in Volt) to be set for that channel. The accepted range for the level depends on the model, the trigger coupling setting and channel sensitivity.

Please note: In some cases the trigger level automatically gets adjusted when changing the trigger coupling if the trigger level is too large for the new coupling setting. For the R&S RTO series also, for digitizing channels, the sensitivity setting can influence the triger level.

Please note:: Setting a trigger level for one of several possible trigger channels does not automatically make this channel the selected trigger channel.

`digitizer_trigger_slope()'

Function for setting or quering the trigger slope of one of the trigger channels of the LeCroy 9400, 9410, 9420, 9424, 9424E, 9450, Waverunner and R&S RTO series digitizers. For all digitizers except the LeCroy 9400 it expects at least a single argument, the trigger channel, see the channels listed for the function digitizer_trigger_channel(). If called with no further argument the current setting for the trigger slope of this channel (or the general slope in the case of the LeCroy 9400) as a number, where 1 stands for positive slope and 0 for negative slope. If called with a second argument it must be either the string "POSITIVE" or "POS" (or the number 1) to set a positive slope or the string "NEGATIVE" or "NEG" (or the number 0) to set a negative trigger slope for that channel.

Please note:: Setting a trigger slope for a trigger channel does not automatically make this channel the selected trigger channel if the device allows to maintain different slope settings for different trigger channels.

`digitizer_trigger_coupling()'

Function for setting or quering the trigger coupling of one of the trigger channels of the LeCroy 9400, 9410, 9420, 9424, 9424E, 9450 and Waverunner digitizers. For all digitizers except the LeCroy 9400 it expects at least a single argument, the trigger channel (see the description of the function digitizer_trigger_channel() for a list of the possible trigger channels). If called with no further arguments the trigger coupling of this channnel (or the general coupling in the case if the LeCroy 9400) gets returned as a number, where 0 stands for AC coupling, 1 for DC coupling, 2 for LF REJ coupling, 3 for HF REF coupling and 4 for HF coupling. To change the coupling for the channel pass the function a second argument, either an integer as it gets returnedon queries, or one of the strings "AC", "DC", "LF REF", "HF REJ" or (except for the LeCroy 9400 and 9410) "HF".

This function does not exist for the R&S RTO series, use digitizer_coupling() instead.

Please note:: Setting a trigger coupling for one of several possible trigger channels does not automatically make this channel the selected trigger channel.

`digitizer_trigger_mode()'

Function for setting or quering the trigger mode of one of the LeCroy 9400, 9410, 9420, 9424, 9424E, 9450 and Waverunner digitizers. If called without an argument the function returns the currently set trigger mode as an integer, if called to set the mode it can either be a string or an integer. The following values are allowed:

`LeCroy 9400'

AUTO or 0
NORM or 1
SINGLE or 2
SEQUENCE or 3

`LeCroy 9410'

`LeCroy 9420'

`LeCroy 9424'

`LeCroy 9424E'

`LeCroy 9450'

AUTO or 0
NORM or 1
SINGLE or 2
SEQUENCE or 3
WRAP or 4

`LeCroy Waverunner'

AUTO or 0
NORM or 1
SINGLE or 2
STOP or 3

`R&S RTO series'

AUTO or 0
NORM or 1

Currently, setting the SEQUENCE or WRAP trigger modes isn't supported.

`digitizer_record_length()'

The function queries (if called with no argument) or sets (if called with an argument) the length of the traces waveform by the digitizer. If called with an argument the value passed to the function will be rounded up to the nearest allowed values if necessary.

For all LeCroy and R&S RTO series oscilloscopes the function can only be called in query mode, i.e. without an argument. For the LeCroy changing the memory size via digitizer_memory_size() afterwards may invalidate the returned value. For the R&S RTO series changing the timebase or time resolution always changes the record length, several other settings may als lead to a change.

`digitizer_record_length_limits()'

This function only exists for the R&S RTO series. It returns an array with 2 integers, the lower (always 1000) and the upper limit the record length can be set to under the current conditions.

`digitizer_memory_size()'

This function is only available for the LeCroy Waverunner and the LeCroy WaveSurfer and can be used to query or set the memory size to be used for storing curves. If the function gets called with an (integer) argument the memory size is set accordingly. Please note that memory sizes can only be set according to an 1-2.5-5 scheme, starting with a minimum memory size of 500 samples (i.e. the lowest memory sizes are 500, 1000, 2500 etc.). If the argument doesn't fit into this scheme the next larger memory size is used and a warning is printed. If called without an argument the function returns the currently set memory size.

Please note that changing the memory size may also change the time resolution (but not the timebase), i.e. when going to a lower memory size the time distance between adjacent measured data points may become larger and vice versa. This in turn may have an effect on the exact positions of previously set windows (see below) as well on the record length as determined by digitizer_record_length().

`digitizer_trigger_position()'

This function only exists for the Tectronics oszilloscopes and is deprecated, please use the digitizer_trigger_delay() function instead.

It queries (if called with no argument) or sets (if called with an argument) the amount of pre-triggering, i.e. the portion of the trace shown with data before the trigger was detected. The function accepts or returns values from the interval [0, 1] (where 0 means that the trigger is at the very first point of the trace, i.e. no pre-trigger is used, and 1 that it's at the last point, i.e. the complete curve is recorded before the trigger).

The function can be called in query mode (i.e. without an argument) only if either it has already been called with an argument or in the EXPERIMENT section.

`digitizer_trigger_delay()'

The function queries (if called with no argument) or sets (if called with an argument) the amount of pre- or post-triggering (in seconds), i.e. the time difference between the start of the acquisition and the trigger. Thus, if called with a positive value, the acquisitions starts by the specified value before the trigger is received (pre-trigger acquisition), if called with a negative value start of the acquisition is delayed by that value relative to the trigger position (post-trigger acquisition).

Please note that the Tektronix oscilloscopes don't allow post-trigger acquisitions, post-trigger acquisitions can only done with the LeCroy oscilloscopes (where the maximum pre-trigger delay is typically 10 times the timebase (5 for the LeCroy WaveSurfer) and the maximum post-trigger delay 10,000 times the timebase setting).

If called without an argument the current setting of the pre- or post-trigger delay is returned.

Please note that, if a trigger delay has been set and a new timebase gets set, the program may get aborted if the requested trigger delay isn't possible with the changed timebase setting.

Since checking the trigger delay requires knowledge about the timebase the oscilloscope is operating at, which may not be available already during the test run, it can happen that the script stops only at the start of the experiment if it detects that an impossible trigger delay is oing to be requested during the experiment.

The function can be called in query mode (i.e. without an argument) only if either it has already been called with an argument or in the EXPERIMENT section.

`digitizer_define_window()'

The function must be used to define a time window to be used in later calls of the functions to measure an area, an amplitude or to fetch a curve from the oscilloscope. Typically, it is called with two arguments, the starting point and the width of the window (both in seconds, where the window width must always be positive).

For the Tektronix oscilloscopes it also may be called with no or only a single argument. If called with no argument the window defined by the cursor pair on the oscilloscopes screen is used. If no width is specified the distance between the pair of cursors is used. In both cases the smallest possible non-zero value for the distance is used if the cursors on the screen are exactly on top of each other.

The function returns an integer number that can be used in later calls to address the window. Thus, you need to store this number in an integer variable to be able to use this window in further calls of digitizer functions.

The allowed ranges of the arguments for the start point and width of the window depend on the timebase setting of the oscilloscope as well as the pre- or post-trigger setting (and, for the Tektronix oscillosopes, the current record length or, for the LeCroy Waverunner, the memory size). The position of the trigger event itself corresponds to a time of exactly 0. Times before the trigger are negative, times after the trigger positive. If a window width is given it has to be positive and the window must fit into the time interval measured by the oscilloscope.

Because the data are measured by the oscilloscope at equally spaced time intervals is not possible to specify arbitrary values for the starting point and window width but they must fit with the current minimum time resolution. If the specified values don't fit the requirement a warning is printed and the position and width are adjusted to the nearest possible values.

Since checking the window settings requires knowledge about the timebase the oscilloscope is operating at as well as the trigger delay, which may not be available already during the test run, it can happen that the script stops only at the start of the experiment if it detects that impossible window settings are going to be requested during the experiment.

`digitizer_change_window()'

This function can be used to change the position and width of an already existing window. As the first parameter the function expects a window number as returned by digitizer_define_window(). The following two arguments are the new position and width for this window. During the experiment neither the position nor the width argument must be specified.

For the Tektronix oscilloscopes the function can also be called without or with only a single argument. If no arguemnt is given the positions of the cursor displayed on the screen are used to redefine the windows new start position and width. If only a new start position is given the distance between the cursors on the screen is used for the window width.

`digitizer_window_position()'

This function can be used to query the position or to set a new position for an already defined window. It expects at least one argument, a window number as returned by digitizer_define_window(). If there is no further argument the position of the window is returned. Otherwise the second parameter is taken to be the new window position.

Since checking the window position requires knowledge about the timebase the oscilloscope is operating at as well as the trigger delay, which may not be available already during the test run, it can happen that the script stops only at the start of the experiment if it detects that an impossible window position is going to be requested during the experiment.

`digitizer_window_width()'

This function can be used to query the width or to set a new width for an already existing window. It expects at least one argument, a window number as returned by digitizer_define_window(). If there is no further argument the width of the window is returned. Otherwise the second parameter is taken to be the new window width.

Since checking the window width requires knowledge about the timebase the oscilloscope is operating at as well as the trigger delay, which may not be available already during the test run, it can happen that the script stops only at the start of the experiment if it detects that an impossible window width is going to be requested during the experiment.

`digitizer_window_limits()'

This function only exists for the R&S RTO series. It returns an array with two values, the earliest possible window position and the possible maximum width.

`digitizer_check_window()'

This function only exists for the R&S RTO series. It expects a window ID as its only argument and returns if using the window under the current circumstances is possible (i.e. if it fits into the measured waveform).

`digitizer_display_channel()'

This function is only implemented for the Tektronix oscilloscopes and can be used during the PREPARATIONS section to tell the program that you want a certain channel or a set of channels to be displayed in any case. It expects a channel name or number (or a comma separated list of channel specifiers) as defined above. There are only certain circumstances where this function is really needed. Normally, the program will not switch off channels. Only if in the test run it is found that some channels are needed for the experiment which aren't switched on but there are already too many other channels displayed which don't seem to be needed the program has to switch off some of them. If in this case the program switches off a channel that you don't want to be off (or that the program erroneously assumes to be useless) you may have to use this function to make sure the channel stays switched on.

`digitizer_channel_state()'

This function is only supported for the R&S RTO series. It allows to switch digitizing and math channels on or off (or query their state). If called with a single argument, the channel it is returned if that channel is on or off. If called with a second, boolean argument the channel is switched on or off accordingly.

Please note: switchin on new channels typically requires memory. which then isn't available for other channels anymore. As a result the record length and thus also the time resolution may become reduced.

`digitizer_start_acquisition()'

This function starts an acquisition sequence of the oscilloscope. Previously measured curves are discarded and new data are sampled until the requested number of averages has been reached or, for the R&S RTO series when riun in Segmented acquisition mode, until the requested number of segments has mean measured. The function can only be used in the EXPERIMENT section of the EDL file.

Please note that for starting an acquisition involving averages for the LeCroy oscilloscopes the function digitizer_averaging() must have been called before starting the acquisition.

`digitizer_available_data()'

This function only exists fro the R&S RTO series. It takes a single argument, either a measurement or nath channel (which must be switched on), and returns the number of samples that can be downloaded from that channel.

`digitizer_get_curve()'

The function fetches a curve from the digitizer. It expects up to two arguments, the channel the data are to be fetched from and, optionally, a window ID as returned by digitizer_define_window() to restrict the returned data to an interval of the measured wavform.

Valid choices of the data channel depend on the model of the digitizer:

`TDS520'

`TDS520A'

`TDS520C'

CH1 or CH2
MATH1, MATH2 or MATH3

`TDS540'

`TDS744A'

`TDS754A'

CH1, CH2, CH3 or CH4
MATH1, MATH2 or MATH3

`LeCroy 9400'

`LeCroy 9410'

`LeCroy 9420'

`LeCroy 9450'

CH1 or CH2
MEM_C or MEM_D
FUNC_E or FUNC_F

`LeCroy 9424'

`LeCroy 9424E'

CH1, CH2, CH3 or CH4
MEM_C or MEM_D
FUNC_E or FUNC_F

`LeCroy Waverunner (LT322, LT342(L), LT262(ML), LT372(L))'

CH1 or CH2
MEM_A, MEM_B, MEM_C or MEM_D
TRACE_A, TRACE_B, TRACE_C or TRACE_D

`LeCroy Waverunner (LT224, LT344(L), LT364(L), LT264(M/ML), LT354(M/ML), LT374(M/L), LT584(M/L))'

CH1, CH2, CH3 or CH4
MEM_A, MEM_B, MEM_C or MEM_D
TRACE_A, TRACE_B, TRACE_C or TRACE_D

`LeCroy WaveSurfer (422, 432, 452)'

CH1 or CH2
MATH

`LeCroy WaveSurfer (424, 434, 454)'

CH1 or CH2, CH3 or CH4
MATH

`Rohde&Schwarz RTO (RTO1002, RTO1012, RTO1022)'

CH1, CH2
MATH1, MATH2, MATH3, MATH4

`Rohde&Schwarz RTO (RTO1002, RTO1012, RTO1022)'

CH1, CH2, CH3, CH4
MATH1, MATH2, MATH3, MATH4

Unless data from a memory channel are fetched the function only returns after a still running acquisition sequence (started by a call of digitizer_start_acquisition()) is finished. The data will b returned as an array of floating point numbers with a number of elements depending on the current settings of the digitizer (timebase, record lengths, memory size etc.) and possibly the window width (if a window is being used).

For the Tektronix oscilloscopes the function positions the cursors at the start and end point of the specified window (or the first and last point if no window as been specified) to give a visual feedback.

This function can only be used in the EXPERIMENT section of an EDL file.

`digitizer_get_curve_fast()'

This function is nearly identical to the function digitizer_get_curve() with the only difference that the cursor are not positioned at the start and end point of the curve to be fetched. For the LeCroy digitizers, where no visual feedback is used, the function is identical to digitizer_get_curve().

`digitizer_get_area()'

This function is currently not implemented for the LeCroy 9400 oscilloscope!

The function returns the area under one of the measured curves, i.e. simply the sum of all values. It expects at least one argument, the oscilloscopes channel the data are to be taken from. The channel that can be used are the same as those that can be used with the digitizer_get_curve() function.

The following, optional arguments are a list of integer variables or 1-dimensional integer arrays, where each number (or array element) is a window ID as returned by digitizer_define_window(), specifying the time interval the area is computed from.

If you pass the function no argument beside the channel number the area of the whole curve is returned. If you pass it a single window number (either by passing it an integer variable or a one-dimensional array of length 1) the function return a floating point variable with the area in the specified window.

Unless you want to fetch an area from a memory channel the function only returns after an acquisition (started by a call of the function digitizer_start_acquisition()) has been finished.

Finally, if you pass the function more than one window identifier (either by passing it more than one integer variable or or one or more integer arrays), it returns a flat, 1-dimensional floating point array with as many elements as there were window identifiers, each element being the area for the corresponding window.

Except for the TDS520 and the LeCroy digitizers this function positions the cursors at the start and end point of the specified window (or the first and last point if no window as been specified) and uses the function built into the digitizer to compute the area. For the TDS520 and the LeCroy digitizers, which miss this built-in function, the curve in the interval is fetched and then used to compute the area. To give some visual feedback also for the TDS520 the cursors are moved to the borders of the interval.

This function can only be used in the EXPERIMENT section of an EDL file.

`digitizer_get_area_fast()'

This function takes the same arguments as the function digitizer_get_area() and also basically does the same. The only difference is that instead of using the function built into the digitizer to compute the area the curve in the specified interval is fetched and the area is computed from these data. This function can be a bit faster because it doesn't set the cursors (which also means that there is no visual feedback). For the LeCroy digitizers, where no visual feedback is used, the function is identical to digitizer_get_area().

This function can only be used in the EXPERIMENT section of an EDL file.

`digitizer_get_amplitude()'

This function is currently not implemented for the LeCroy 9400 oscilloscope.

The function returns the amplitude, i.e. the difference between the maximum and minimum voltage, from the digitizer. The function takes at least one argument, the channel the data are to be fetched from. Valid choices of the data channel depend on the model and are the same as for the digitizer_get_curve() function.

If you pass the function no argument beside the channel number the amplitude of the whole curve is returned. If you pass it a single window number (either by passing it an integer variable or a one-dimensional array of length 1) the function returns a floating point variable with the amplitude in the specified window.

Finally, if you pass the function more than one window identifier (either by passing it more than one integer variable or one or more integer arrays), it returns a flat, 1-dimensional floating point array with as many elements as there were window identifiers, each element being the amplitide for the corresponding window.

Unless you want to fetch an amplitude from a memory channel the function only returns after an acquisition (started by a call of the function digitizer_start_acquisition()) has been finished.

Except for the TDS520 and the LeCroy digitizers this function positions the cursors at the start and end point of the specified window (or the first and last point if no window as been specified) and uses the function built into the digitizer to compute the amplitude. For the TDS520 and the LeCroy digitizers, that miss this built-in function the curve in the interval is fetched and then is used to compute the amplitude. To give some visual feedback also for the TDS520 the cursors are moved to the borders of the interval.

This function can only be used in the EXPERIMENT section of an EDL file.

`digitizer_get_amplitude_fast()'

This function is nearly identical to digitizer_get_amplitude() except that the function to compute amplitudes built into the digitizer isn't used and the cursors aren't positioned at the start and end of the time interval. It is not implemented for the LeCroy digitizers, where no visual feedback is used.

This function is only available for the R&S RTO series.

`digitizer_get_segments()'

This function is only available for the R&S RTO series. The device allows fast acquisition of a number of waveforms, called "Ultra Segmentation". With this function a a set of such segments can be downloaded. It expects at least one argument, the channel the waveforms are to be downloaded from. This can be one of the digitizing channels. An optional second argument is a window ID. The function returns a two-dimensional array with as many waveforms as segments got downloaded. Before a download is started the function waits for a running acquisition to finish.

`digitizer_get_segment_area()'

`digitizer_get_segments()'

This function is only available for the R&S RTO series. This function allows to obtain the areas (sums of the data points) for the available segments. It expects at least one argument, the channel of the segments. This can be any of the digitizing channels. If no further argument is given the function returns a 1-dimensional array with the areas for each of the segments.

It may also be called with either a set of window IDs or an array of window IDs. If called with a single window ID (or an array with only a single element) also a 1-dimensional array is returned with the areas in the window range of the segments.

If called with a set of window IDs or an array with more than one window ID a 2-dimensional array us returned, with one sub-array for each segment and each sub-array containing the areas for the windows.

`digitizer_get_segment_amplitude()'

`digitizer_get_segments()'

This function is only available for the R&S RTO series. This function allows to obtain the amplitudes (differences between largest and smallest data point) for the available segments. It expects at least one argument, the channel of the segments. This can be any of the digitizing channels. If no further argument is given the function returns a 1-dimensional array with the amplitudes for each of the segments.

It may also be called with either a set of window IDs or an array of window IDs. If called with a single window ID (or an array with only a single element) also 1-dimensional array is returned with the amplitides in the window range of the segments.

If called with a set of window IDs or an array with more than one window ID a 2-dimensional array us returned, with one sub-array for each segment and each sub-array containing the amplitudes for the windows.

`digitizer_available_segments()'

`digitizer_get_segments()'

This function is only available for the R&S RTO series. It takes no arguments and returns how many segments are available for download.

`digitizer_run()'

Usually, during an experiment the Tektronix digitizers start acquisitions after a call of digitizer_start_acquisition() and then stop when it's done. To have the digitizer running constantly following an acquisition (at least up to the next call of digitizer_start_acquisition()) call this function after the acquisition is done. It accepts no arguments and can only be used in the EXPERIMENT section. The function does not exist for the LeCroy oscilloscopes.

For the R&S RTO series the function starts a contimuous run which can only be stopped using a call of digitizer_stop(). Don'try to fetch waveforms while the device is in a continuous run since downloding waveforms requires that the device is stopped.

`digitizer_stop()'

This function only exists for the R&S RTO series. It takes no argument and stops a contimuous run of the oscilloscope.

`digitizer_copy_curve()'

This function is available for the Tektronix and all LeCroy digitizers except the LeCroy 9400. It allows to save a curve from on of the normal measurement or MATH / FUNC channels to one of the REF/MEM channels. It takes two arguments, first the source channel, i.e. the channel to copy the data from, which must be (depending on the model of the digitizer)

`TDS520'

`TDS520A'

`TDS520C'

CH1 or CH2
MATH1, MATH2 or MATH3

`TDS540'

`TDS744A'

`TDS754A'

CH1, CH2, CH3 or CH4
MATH1, MATH2 or MATH3

`LeCroy 9410'

`LeCroy 9420'

`LeCroy 9450'

CH1 or CH2
FUNC_E or FUNC_F

`LeCroy 9424'

`LeCroy 9424E'

CH1, CH2, CH3 or CH4
FUNC_E or FUNC_F

`LeCroy Waverunner (LT322, LT342(L), LT262(ML), LT372(L))'

CH1 or CH2
TRACE_A, TRACE_B, TRACE_C or TRACE_D

`LeCroy Waverunner (LT224, LT344(L), LT364(L), LT264(M/ML), LT354(M/ML), LT374(M/L), LT584(M/L))'

CH1, CH2, CH3 or CH4
TRACE_A, TRACE_B, TRACE_C or TRACE_D

`LeCroy WaveSurfer (422, 432, 452)'

CH1 or CH2

`LeCroy WaveSurfer (424, 434, 454)'

CH1 or CH2, CH3 or CH4

The second argument is the channel the data are to be copied to, i.e. one from

`TDS520'

`TDS520A'

`TDS520C'

`TDS540'

`TDS744A'

`TDS754A'

REF1, REF2, REF3 or REF4

`LeCroy 9410'

`LeCroy 9420'

`LeCroy 9424'

`LeCroy 9424E'

`LeCroy 9450'

MEM_C or MEM_D

`LeCroy Waverunner (all models)'

MEM_A, MEM_B, MEM_C or MEM_D

`LeCroy WaveSurfer (all models)'

M1, M2, M3, M4

This function can only be used in the EXPERIMENT section of an EDL script and is probably most useful for being able to start a new acquisition before fetching the data from the prvious one, thus reducing the time required to do an experiment.

`digitizer_math_function()'

This function is only available for the R&S RTO series. It allows to query or set the function of one of the math functions. Its first argument is always one of the math channels. If there's no further argument the currently used function is returned as a string (or the empty string if no function is active). If passed a second argument, a string with a formula, the function of the math channel is set accordingly. A very simple formula would be e.g. "c1w1-c2w1" to make the math channel calculate the difference between the first waveforms of the first and second input channel. For a description of functions that can be used see the manual for the device.

Please note: setting a function for a math channel does not als switch it on. This has to be done using the function digitizer_channel_state().

`digitizer_lock_keyboard()'

This function is only available for the Tectronix oszilloscopes. Usually, during an experiment the keyboard of the digitizer is locked. But for situations where it would be useful to be able to control the digitizer also via its keyboard it can be unlocked (and also re-locked) from within the program. To unlock the keyboard call this function with an argument of 0 or "OFF", to re-lock the keyboard call it again with a non-zero argument, "ON" or no argument at all.

`digitizer_display_enable()'

This function is only available for the R&S RTO series. This device allows to disable display updates while in remote mode (a static graphic is shown instead). Using this function it can be queried or set if the display is to be enabled or disabled.

`digitizer_trigger_out_pulse_state()'

This function is only available for the R&S RTO series. The device can emit a pulse some time after it triggered. This function can be used to query or set if such a pulse is created.

`digitizer_trigger_out_pulse_length()'

This function is only available for the R&S RTO series. The device can emit a pulse some time after it triggered. This function can be used to query or set the length of this pulse. The possible range of the length is 4 ns to 1 ms.

`digitizer_trigger_out_pulse_polarity()'

This function is only available for the R&S RTO series. The device can emit a pulse some time after it triggered. This function queries or sets the polirity of the pulse. Possible settings are "POSITIVE" (or 0) and "NEGATIVE" (or 1).

`digitizer_trigger_out_pulse_delay()'

This function is only available for the R&S RTO series. The device can emit a pulse some time after it triggered. This function queries or sets the delay between the trigger and the emission of the pulse. The minimum delay depends on all kinds of circumstances but can be never less than 800 ms or larger than 1 s.

`digitizer_trigger_out_pulse_delay_limits()'

This function is only available for the R&S RTO series. It takes no arguments and returns an array with two values, the minimum and maximum delay between the trigger and the trigger out pulse posssible under the current circumstances.

This document was generated by Jens Thoms Toerring on September 6, 2017 using texi2html 1.82.