SAMPle Subsystem

The SAMPle commands are used with the TRIGger commands to set up the triggering parameters. Use the SAMPle commands to set a sample count, sample source, and delay time for triggered sampling.

It is recommended that all triggered measurements be made using an appropriate fixed manual range. That is, turn autorange off (SENSe:<function>:RANGe:AUTO OFF), or set a fixed range using the SENSe:<function>:RANGe, CONFigure, or MEASure command.

Command Summary

SAMPle:COUNt

SAMPle:COUNt:PRETrigger

SAMPle:SOURce

SAMPle:TIMer

SAMPle:COUNt {<count>|MIN|MAX|DEF}
SAMPle:COUNt? [{MIN|MAX|DEF}]

Specifies the number of measurements (samples) the instrument takes per trigger.

Parameter Typical Return

1 to 1,000,000 (1x106). Default: 1. (34460A/61A)
1 to 1,000,000,000 (1x109). Default: 1. (34465A/70A)

+1

Return ten sets of four resistance measurements, using an external trigger to start each measurement set:

CONF:RES 1E6
SAMP:COUN 4
TRIG:COUN 10
TRIG:SOUR EXT;SLOP NEG
READ?

Typical Response: +1.00520000E+06, … (40 measurements)

SAMPle:COUNt:PRETrigger {<count>|MIN|MAX|DEF}
SAMPle:COUNt:PRETrigger? [{MIN|MAX|DEF}]

Allows collection of the data being digitized before the trigger. Reserves memory for pretrigger samples up to the specified number of pretrigger samples.

It is recommended that all triggered measurements be made using an appropriate fixed manual range. That is, turn autorange off (SENSe:<function>:RANGe:AUTO OFF), or set a fixed range using the SENSe:<function>:RANGe, CONFigure, or MEASure command.

Parameter Typical Return
0 to 1,999,999. Default: 0. +999999

Configure AC voltage measurements using the 100 V range. Set the sample count to 10,000 and the pretrigger sample count to 5000 (5000 samples are taken before the trigger, and 5000 after). The trigger occurs when the input signal reaches 0.75 volts.

CONF:VOLT:AC
VOLT:AC:RANG 100
SAMP:COUN 10000
SAMP:COUN:PRET 5000
TRIG:SOUR INT
TRIG:LEV 0.75
INIT

See Also

SAMPle:COUNt

SAMPle:SOURce {IMMediate|TIMer}
SAMPle:SOURce?

Determines sample timing, with TRIGger:DELay and SAMPle:TIMer to determine sample timing, when the sample count is greater than one.

It is recommended that all triggered measurements be made using an appropriate fixed manual range. That is, turn autorange off (SENSe:<function>:RANGe:AUTO OFF), or set a fixed range using the SENSe:<function>:RANGe, CONFigure, or MEASure command.

Parameter Typical Return
{IMMediate|TIMer}. Default: IMMediate. IMM or TIM

Set sample source to timer. The INIT command sets the meter to the "wait-for-trigger" state. When a trigger is received from the selected trigger source, the instrument starts taking periodic samples after the trigger delay.

SAMP:SOUR TIM
SAMP:TIM 0.1
INIT

Operation

In all cases, the first sample is taken one trigger delay time after the trigger (the delay being set with the TRIGger:DELay command). Beyond that, the timing mechanism depends on whether you select IMMediate (default) or TIMer as the source:

The sample timing is not deterministic because the delay time (set with TRIGger:DELay) is inserted after each sample completes. The actual time required to take each sample depends on the integration time and autoranging time. In this case, the SAMPle:TIMer command has no effect.

The sample timing is deterministic because the start of each sample is determined by the sample interval, set with the SAMPle:TiMer command (TRIGger:DELay affects only the start of the first sample). Integration and autoranging affect the sampling time for each sample, but not the sample interval as long as the sample interval is longer than the sampling time.

Remarks

See Also

TRIGger:COUNt

TRIGger:DELay

TRIGger:SOURce

SAMPle:COUNt

SAMPle:TIMer

SAMPle:TIMer {<interval>|MIN|MAX|DEF}
SAMPle:TIMer? [{MIN|MAX|DEF}]

Sets a sample interval for timed sampling (SAMPle:SOURce TIMer) when the sample count is greater than one.

The first sample is taken one trigger delay time after the trigger (delay set by TRIGger:DELay). The second sample starts one sample interval after the start of the first sample, and so forth, as shown below:

Note that the sample timing is determinant because the start of each sample is determined by the sample interval. Integration and autoranging affect the sampling time for each sample, but not the sample interval as long as the sample interval is longer than the sampling time. Periodic sampling continues until the sample count (set with the SAMPle:COUNt command) is satisfied.

It is recommended that all triggered measurements be made using an appropriate fixed manual range. That is, turn autorange off (SENSe:<function>:RANGe:AUTO OFF), or set a fixed range using the SENSe:<function>:RANGe, CONFigure, or MEASure command. When autorange is left on, the starting time of a sample becomes uncertain (when a range change occurs) and when ranging exceeds the interval between samples; then all subsequent samples become offset from their desired start points.

Parameter Typical Return
<interval> MIN (see bullet points below) to 3600 seconds (~1 µs steps). +3.60000000E+003

Set the sample interval to 0.1 seconds. INIT sets the meter to the "wait-for-trigger" state. When a trigger is received from the selected trigger source, the instrument waits the trigger delay time, and then takes readings every 0.10 seconds until the sample count is satisfied.

SAMP:SOUR TIM
SAMP:TIM 0.1
INIT

See Also

TRIGger:COUNt

TRIGger:DELay

TRIGger:SOURce

SAMPle:COUNt

SAMPle:SOURce