IEEE-Common Commands Instrument Setup and Status
Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Fifth Edition 59
command:
*IDN?
syntax: *IDN?
description: The IDeNtification query *IDN? gets the instrument identification over the interface.
parameters: none
response: The identification terminated by <END>:
For example.
Agilent Technologies
mmmm
ssssssss
rrrrrrrrrr
manufacturer
instrument model number (for example 8164B)
serial number
firmware revision level
example: *IDN? → Agilent Techologies,mmmm,ssssssss,rrrrrrrrrr<END>
NOTE
The Agilent 8163A, Agilent 8164A, and Agilent8166A will always return Agilent Technologies as the 
manufacturer. This will not be affected by the transition of these instruments to Agilent Technologies. This will 
allow programs that use this string to continue functioning.
See “:SLOT[n]:HEAD[n]:IDN?” on page 82 for information on module identity strings.
command:
*OPC
syntax: *OPC
description: The instrument parses and executes all program message units in the input queue and 
sets the operation complete bit in the standard event status register (SESR). This com-
mand can be used to avoid filling the input queue before the previous commands have fin-
ished executing. 
Some module firmware includes commands that set a  "StatNOPC" flag during execution 
to indicate that the module is busy. *OPC blocks the GPIB bus to all commands until every 
module hosted by the instrument is no longer busy.
The following actions cancel the *OPC command (and put the instrument into Operation 
Complete, Command Idle State):
•Power-on
• the Device Clear Active State is asserted on the interface.
•*CLS
•*RST
parameters: none
response: none
example: *OPC