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FETCh[
<chan>
]
The FETCh? command is used in conjunction with the INITiate:IMMediate
command to obtain readings. The FETCh:COUNt command is used to indicate how
many readings are available.
Subsystem
Syntax
FETCh[<
chan
>]? [query only]
:COUNt? [query only]
:RECover? [query only]
FETCh?
FETCh[<chan>]? returns readings from the specified channel in the format set by
the FORMat:DATA command. An INITiate:IMMediate command must have been
issued previously or else error -230, "Data corrupt or stale" will occur.
Parameters
Parameter
Name
Parameter
Type
Range of
Values
Default
Units
chan
numeric 1 | 2 none
Comments • If measurements are still being taken when the FETCh? command is sent, the
command will wait until readings have completed and will then return the data.
Note that this could generate a deadlock error message if either the arming source
or the trigger source is set to BUS, because a software trigger could not break in
after FETCh? is sent.
• If desired, the negative transition of the BUSY bit (bit 8) in the
STATus:OPERation:CONDition register can be used to determine when
measurements have completed so a FETCh? could execute without delay or threat
of deadlock. This status register bit can be enabled to generate an SRQ when
readings are complete, and thus interrupt the controller. See the STATus
subsystem in the Command Reference for more details.
• If error -230 "Data corrupt or stale" occurs and you must read the data, the
FETCh:RECover? command can be used to force data read with no error.
• FETCh? or FETCh1? will return readings from channel 1 only. FETCh2? will
return readings from channel 2 only.
224 Command Reference FETCh[
<chan>
] Subsystem