Fluke PM6685 Outdoor Timer User Manual


 
as long as there is unfetched data in any
of the status event registers.
The Requested Service bit, RQS, is set true
when a service request has been signalled.
If you read the status byte via a Serial Poll,
bit 6 represents RQS. Reading the status
byte with a serial poll will set the RQS bit
false, showing that the status byte has been
read.
The Master Summary Status bit, MSS, is
set true if any of the bits that generates
SRQ is true. If you read the status byte us
-
ing *STB?, bit 6 represents MSS. MSS re
-
mains true until all event registers are
cleared and all queues are empty.
Setting up the Counter to
Report Status
Include the following steps in your pro-
gram when you want to use the status re-
porting in CNT-8X:
*CLS Clears all event registers and the er-
ror queue
*ESE <bit mask> Selects what condi-
tions in the Standard Event Status register
should be reported in bit 5 of the status
byte
:STATus:OPERation:ENABle <bit
mask> Selects which conditions in the
Operation Status register should be re
-
ported in bit 7 of the status byte
:STATus:QUEStionable:ENABle
<bit mask> Selects which conditions in
the Questionable Status register should be
reported in bit 3 of the status byte
:STATus:DREGister0:ENABle
<bit mask> Selects which conditions
in Device Register 0 should be reported in
bit 0 of the status byte
*SRE <bit mask> Selects which bits
in the status byte should cause a Service
Request
A programming example using status re
-
porting is available in the Programming
Examples in chapter 4.
Reading and Clearing Status
n
Status Byte
As explained earlier, you can read the sta
-
tus byte register in two ways:
Using the Serial Poll (IEEE-488.1 de
-
fined).
Response:
Bit 6: RQS message, shows that the
counter has requested service via the
SRQ signal.
Other bits show their summary mes-
sages
A serial poll sets the RQS bit
FALSE, but does not change other
bits.
Using the Common Query *STB?
Response:
Bit 6: MSS message, shows that
there is a reason for service request.
Other bits show their summary mes
-
sages.
Reading the response will not alter
the status byte.
n
Status Event Registers
You read the Status Event registers with
the following queries:
6-18 Status Subsystem
Using the Subsystems