4. REMOTE OPERATION
Page 167
© 1998-2008 DH Instruments, a Fluke Company
The status byte register can be read using the “*STB?” query, or by performing a
serial poll on the IEEE-488 bus. If you read this using a serial poll then bit 6 is
the RQS. If the “
∗
STB?” query is used, then bit 6 is the MSS bit. All of the other
bits are common to both types of query.
Each of these status bits can cause an SRQ to occur. The Service Request
Enable Register (“
∗
SRE” program message) determines which of these flags are
able to assert the SRQ line. This enabled register has a matching set of bits that
each will enable the designated bit to cause an SRQ, except for the RQS/MSS
bit(s) which cannot cause an SRQ. If you set this register to 20 ($14 hex), an
SRQ will occur if the MAV or the ERROR bit are set. The description of these
bits are given as:
•
OPER
: OPERational event register summary bit (Bit 7)
This bit is not supported by PG7000.
•
RQS
: Requested Service (Bit 6)
Indicates that the SRQ line of the IEEE-488 interface has been
asserted by PG7000. This bit is cleared when a serial poll is performed
on PG7000, and is a part of the status byte register when read using
a serial poll. This bit does not apply if the COM1 port is being used.
•
MSS
: Master Summary Status (Bit 6)
Indicates that an event or events occurred that caused PG7000 to
request service from the Host, much like the RQS bit. Unlike the
RQS bit, it is READ ONLY and can be only cleared when the
event(s) that caused the service request are cleared.
•
ESB
:
Event Summary Bit (Bit 5)
Indicates if an enabled bit in the Standard Event Status Register
became set. (See the section below.)
•
MAV
: Message Available Bit (Bit 4)
Indicates that at least one reply message is waiting in the PG7000
IEEE-488 output queue.
•
ERR
:
Error Queue not empty (Bit 2)
Indicates that at least one command error message is waiting in the
PG7000 IEEE-488 error message queue. Use the “SYSTem:ERRor?”
query to get this message.
4.4.1.2
STANDARD EVENT REGISTER
PG7000 contains an 8 bit Standard Event Register that reflects specific PG7000
events that are not RPT dependent. Enabled events in this register will set or
clear the ESB bit of the status byte register.
Table 27
.
Standard Event Register
PON
(128)
URQ
(64)
CMD
(32)
EXE
(16)
DDE
(8)
QYE
(4)
RQC
(2)
OPC
(1)
