Stb And Sre - Fluke 5520A Programmer's Manual

Checking 5520A Status (cont)

STB and SRE

7 6
RQS
0
MSS
RQS Requesting service. The RQS bit is set to 1
whenever bits ESB, MAV, EAV, or ISCB change
from 0 to 1 and are enabled (1) in the SRE. When
RQS is 1, the 5520A asserts the SRQ control line
on the IEEE-488 interface. You can do a serial poll
to read this bit to see if the 5520A is the source of
an SRQ.
MSS Master summary status. Set to 1 whenever bits
ESB, MAV, EAV, or ISCB are 1 and enabled (1) in
the SRE. This bit can be read using the *STB?
command in serial remote control in place of doing
a serial poll.
ESB Set to 1 when one or more enabled ESR bits are 1.
MAV Message available. The MAV bit is set to 1
whenever data is available in the 5520A's
IEEE-488 interface output buffer.
EAV Error available. An error has occurred and an error
is available to be read from the error queue by
using the ERR? query.
ISCB One or more enabled ISCR bits are 1.
For RS-232, transmitting the ^P character (hold
down the <Ctrl> key and press P) returns the
SPLSTR (Serial Poll String) and the status byte.
5 4
ESB MAV EAV
9
3 2 1
ISCB 0
0
0
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