FETCh[<chan>]

Subsystem Syntax

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.

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

Parameter

Range of

Default

Name

Type

Values

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

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HP E1429A manual Command Reference FETChchan Subsystem