Keithley 7001, Instruction Manual

Page: 165 / 353

IEEE-488 Reference
5-46
5.10.6
*OPC

operation complete
To set the Operation Complete bit in the Standard Event Status Register after all overlapped
commands are complete.
*OPC
On power-up, or when *CLS or *RST is executed, the Model 7001 goes into the Operation
Complete Command Idle State (OCIS). In this state there are no pending overlapped comamnds.
There are three overlapped commands used by the Model 7001:
:INITiate
:INITiate:CONTinuous ON
*TRG
When the *OPC command is sent, the Model 7001 exits from OCIS and enters the Operation
Complete Command Active State (OCAS). In OCAS, the instrument continuously monitors the
No-Operation-Pending flag. After the last pending overlapped command is complete (No-Oper-
ation-Pending flag set to true), the Operation Complete (OPC) bit in the Standard Event Status
Register sets, and the instrument goes back into OCIS.
Note that the instrument always goes into OCAS when *OPC is executed. If there are no pend-
ing command operations (e.g. trigger model in idle state), the Model 7001 immediately sets the
OPC bit and returns to OCIS.
When used with the :INITiate or :INITiate:CONTinuous ON command, the OPC bit of the Stan-
dard Event Status Register will not set until the Model 7001 goes back into the idle state. The
initiate operations are not considered finished until the instrument goes into the idle state.
When used with the *TRG comamnd, the OPC bit will not set until the operations associated
with the *TRG command (and the initiate command) are finished. The *TRG command is con-
sidered to be finished when the Device Action completes or when operation stops at a control
source to wait for an event (see Trigger Model in paragraph 5.7).
In order to use *OPC exclusively with the *TRG command you will have to first force the com-
pletion of the initiate command so that only the *TRG command is pending. To do this, use the
:INITiate:CONTinuous ON command to start the scan and then send the :ABORT command.
The abort command places the instrument in the idle layer, which (by definition) completes the
initiate command. Since continuous initiation is on, operation will continue on into the Trigger
Model. After sending the *TRG command, the OPC bit will set when the *TRG command is
finished.
Purpose
Format
Description
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