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CHAPTER 5:
Computer Interface Operation
Model 648 Electromagnet Power Supply
OPC?
Operation Complete Query
OPC?[term]
Returned
1[term]
Remarks
Has no interaction with bit 0 (OPC) of the Standard Event Status Register. If sent at
the end of a command sequence, the bus will be held until the instrument completes
the operation that was initiated by the command sequence. Once the sequence is
complete a 1 will be placed in the output buffer. Refer to section 5.2.5.1 for more
information.
RST
Reset Instrument Command
Input
RST[term]
Remarks
Sets controller parameters to power-up settings. Use the DFLT command to set fac-
tory defaults.
SRE
Service Request Enable Register Command
Input
SRE <bit weighting>[term]
Format
nnn
Remarks
The Service Request Enable Register determines which summary bits of the Status
Byte may set bit 6 (RQS/MSS) of the Status Byte to generate a Service Request. This
command programs the enable register using a decimal value that corresponds to the
binary-weighted sum of all bits in the register. Refer to section 5.2.7.2.
SRE?
Service Request Enable Register Query
Input
SRE?[term]
Returned
<bit weighting>[term]
Format
nnn (Refer to command for description)
STB?
Status Byte Query
Input
STB?[term]
Returned
<bit weighting>[term]
Format
nnn
Remarks
This command is similar to a Serial Poll except it is processed like any other instru-
ment command. It returns the same result as a Serial Poll except that the Status Byte
bit 6 (RQS/MSS) is not cleared. Refer to section 5.2.5.2.
TST?
Self-Test Query
Input
TST?[term]
Returned
<status>[term]
Format
n
<status>
0 = no errors found, 1 = errors found
Remarks
The Model 648 reports status based on test done at power up.
WAI
Wait-to-Continue Command
Input
WAI[term]
Remarks
This command is not supported in the Model 648.
