Agilent Technologies 3458A User Manual page 179

event
The event choices are:
event
Parameter
OFF
ICOMP
ONCE
APER
BCOMP
SRQ
RCOMP
Power-on event = ICOMP.
Default event = ICOMP.
polarity
Specifies the polarity of the EXTOUT signal. The choices are:
polarity
Parameter
NEG
POS
Power-on polarity = NEG.
Default polarity = NEG.
•
Remarks
All events except APER generate a 1 µs pulse on the EXTOUT connector. If
APER is selected, the A/D's aperture waveform is output directly. The leading
edge of the EXTOUT signal is the response to the event. Refer to "EXTOUT"
in Chapter 4 for a detailed description of the above events.
•
When a status event sets the SRQ bit in the status register, that bit remains set
until cleared (CSB command, for example). When specified, the EXTOUT SRQ
pulse occurs whenever any status event occurs that has been enabled to assert
SRQ (RQS command). The EXTOUT SRQ pulse does not necessarily occur
whenever the SRQ bit is set; it occurs whenever an enabled status event occurs.
•
Query Command. The EXTOUT? query command returns two responses
separated by a comma. The first response indicates the currently specified
EXTOUT event. The second response indicates the polarity. Refer to "Query
Commands" near the front of this chapter for more information.
Numeric
Query
Equiv. Description
0 None; EXTOUT is disabled
1 Input complete (1µs pulse after A/D converter has
integrated each reading or, for direct- or sub-sampling,
after the track and hold has acquired the input signal)
2 Outputs a 1µs pulse upon execution of the EXTOUT
ONCE command; the event then becomes OFF
3 Aperture waveform (a level indicating when the A/D
converter is making a measurement)
4 Burst complete (1µs pulse following a group of readings)
5 Status event occurred (1µs pulse whenever a status
register event occurs that has been enabled to assert the
GPIB SRQ). (See second Remark below.)
6 Reading complete (1µs pulse after each reading)
Numeric
Query
Equiv. Description
0 Generates a low-going TTL signal
1 Generates a high-going TTL signal
Chapter 6 Command Reference
EXTOUT
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