HP VXI 75000 C Series, User'S And Scpi Programming Manual

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100 Programming the HP E1415 for PID Control Chapter 3
Bit 5 (ESB)
bit value 32
10
Read the Standard Event Group’s Event Register using
the *ESR? command. This will return bit values for
events which have occurred in this group. After
reading, this status register is cleared.
Note that bits 2 through 5 in this group indicate error
conditions. If any of these bits are set, error messages
will be found in the Error Queue. Use the SYST:ERR?
command to read these.
Bit 7 (OPR)
bit value 128
10
Read the Operation Status Group’s Event Register
using the STAT:OPER:EVENT? command. This will
return bit values for events which have occurred in this
group. After reading, the Event Register is cleared.
Clearing the Enable
Registers
To clear the Enable Registers execute:
STAT:PRESET
for Operation Status and
Questionable Data Groups
*ESE 0
for the Standard Event Group
*SRE 0
for the Status Byte Group
The Status Byte
Group’s Enable
Register
The Enable Register for the Status Byte Group has a special purpose. Notice
in Figure 3-12 how the Status Byte Summary bit wraps back around to the
Status Byte. The summary bit sets the RQS (request service) bit in the Status
Byte. Using this Summary bit (and those from the other status groups) you
can poll the Status Byte and check the RQS bit to determine if there are any
status conditions which need attention. In this way the RQS bit is like the
HP-IB’s SRQ (Service Request) line. The difference is that while executing
an HP-IB serial poll (SPOLL) releases the SRQ line, executing the *STB?
command does not clear the RQS bit in the Status Byte. You must read the
Event Register of the group who’s summary bit is causing the RQS.
Reading Status
Groups Directly
You may want to directly poll status groups for instrument status rather than
poll the Status Byte for summary information.
Reading Event Registers
The Questionable Data, Operation Status, and Standard Event Groups all
have Event Registers. These Registers log the occurrence of even temporary
status conditions. When read, these registers return the sum of the decimal
values for the condition bits set, then are cleared to make them ready to log
further events. The commands to read these Event Registers are:
STAT:QUES:EVENT?
Questionable Data Group Event
Register
STAT:OPER:EVENT?
Operation Status Group Event
Register
*ESR?
Standard Event Group Event
Register