:MEASure:OSCilloscope:DELTatime

Meas. mode:
Scope
Package License:
L-RND
L-MFG
Waveform type:
NRZ
PAM4
Flex Apps:
FlexDCA
FlexRT
Delta Time Commands

Command Syntax

:MEASure:OSCilloscope:DELTatime

Query Syntax

:MEASure:OSCilloscope:DELTatime?

Description

Moves the delta time (time delay) measurement between two edges to the top of the Results table. In Oscilloscope mode, this measurement may be compatible with PAM4 signals, depending on the PAM4 waveform. Displays the measurement if it is not already shown on the table. The query form of the command returns the measured value. Delta time is the time difference from the first specified edge on source one to the next specified edge on source two. Use the child commands to specify the source waveforms and their associated edge number (:OSCilloscope:DELTatime:ENUMber), direction :OSCilloscope:DELTatime:EDIRection, and threshold :OSCilloscope:DELTatime:ETHReshold. Sources can be any displayed waveform, waveform memory, or function. For example, CHAN1A, WMEMory1, or FUNCtion1. Use the child commands to set the measurement parameters before sending the parent command. Use :MEASure:TBASe:METHod to change the definition of the waveform's top/base. Use :MEASure:THReshold:METHod to change the definition of the waveform's threshold.

PAM4 Compatibility. Because this measurement is based on waveform top and base levels and the passing of the waveform's edge through proximal, mesial, and distal thresholds, the measurement is not designed for PAM4 signals. However, the measurement may be able to be made on PAM4 signals if the waveform top and base definitions are manual set. This can be attempted using the following commands: :MEASure:TBASe:METHOd, :CHANnel:UDEFined:TOP, and :CHANnel:UDEFined:BASe commands. Additionally, delta time measurements must be made using the same top and base.

Measurement Identification

Avoid subtle programming errors! To ensure that the correct measurement is installed or queried, always explicitly identify a measurement when installing a measurement or querying a measured value, status, or detail. To identify a measurement, specify the measurement's source waveform (:SOURce child command). With some measurements, you may also need to specify other identifying values. Generally, when selecting a measurement using FlexDCA's GUI, if a dialog appears prompting you to select values, you should explicitly specify these values when remotely identifying the measurement. More information.

For example, to return the status of the measurement, :MEASure:OSCilloscope:DELTatime:

flex.write(':MEASure:OSCilloscope:DELTatime:SOURce CHAN1A')
if flex.query(':MEASure:OSCilloscope:DELTatime:STATus?') == 'CORR';
    measurement = flex.query(':MEASure:OSCilloscope:DELTatime?')
else:
	details = flex.query(':MEASure:OSCilloscope:DELTatime:STATus:DETails?')
	reason = flex.query(':MEASure:OSCilloscope:DELTatime:STATus:REASon?')

Child commands for measurement identification:

  • :MEASure:OSCilloscope:DELTatime:SOURce1
  • :MEASure:OSCilloscope:DELTatime:SOURce2
  • :MEASure:OSCilloscope:DELTatime:ENUMber1
  • :MEASure:OSCilloscope:DELTatime:ENUMber2
  • :MEASure:OSCilloscope:DELTatime:EDIRection1
  • :MEASure:OSCilloscope:DELTatime:EDIRection2
  • :MEASure:OSCilloscope:DELTatime:ETHReshold1
  • :MEASure:OSCilloscope:DELTatime:ETHReshold2
  • :MEASure:OSCilloscope:DELTatime:REGion

Example Command Sequence

This sequence defines source one's edge number, direction, and threshold followed by source two's edge number, direction, and threshold. The delta time measurement is then started and the measurement result returned.

:SYSTem:MODE OSCilloscope
:MEASure:OSCilloscope:DELTatime:SOURce1 CHAN1A
  //  Defines first measurement edge
:MEASure:OSCilloscope:DELTatime:ENUMber1 2
:MEASure:OSCilloscope:DELTatime:EDIRection1 RISing
:MEASure:OSCilloscope:DELTatime:ETHReshold1 MIDDle
  //  Defines second measurement edge
:MEASure:OSCilloscope:DELTatime:SOURce2 WMEMory1
:MEASure:OSCilloscope:DELTatime:ENUMber2 3
:MEASure:OSCilloscope:DELTatime:EDIRection2 FALLing
:MEASure:OSCilloscope:DELTatime:ETHReshold2 MIDDle
  //  Perform measurement
:MEASure:OSCilloscope:DELTatime
:MEASure:OSCilloscope:DELTatime?

Measurement Ready?

To confirm that the measurement is ready to read, you can query the measurement's status:

if ('CORR' in Flex.query(':MEASure:OSCilloscope:DELTatime:STATus?')):
	measurement = Flex.query(':MEASure:OSCilloscope:DELTatime?')

If averaging is turned on (:ACQuire:AVERaging), you can also confirm if the measurement result is ready by comparing the number of specified averages (:ACQuire:ECOunt?) versus the number of measurement sweeps that have occurred (:MEASure:OSCilloscope:DELTatime:COUNt?). The technique uses the :COUNt? common measurement query. For example,

if (Flex.query(':MEASure:OSCilloscope:DELTatime:COUNt?') >= Flex.query(':ACQuire:ECOUNt?')):
	measurement = Flex.query(':MEASure:OSCilloscope:DELTatime?')

You can also use an acquisition limit lest to test that a number of waveform samples, or pattern acquisitions have completed before returning a measurement. Refer to the :LTESt:ACQuire:CTYPe command.

Common Measurement Child Queries

This command supports the use of the following common measurement queries: :LOCation?, :COUNt?, :MAXimum?, :MINimum?, :MEAN?, and :SDEViation?.