Technical data

Status Byte
The Status Byte is the summary register to which the other registers report. Each
reporting register is assigned a bit in the Status Byte Register.
The bits in the Status Byte byte have the following meaning:
Table 1
Bit Mnemonic Description
0 Not used
1 Not used
2 EAV Error available: The error
queue contains at least
one message.
3 QUES A bit has been set in the
Questionable Data Status
register (indicates that a
signal is of questionable
quality).
4 MAV Message available: There
is at least one message in
the message queue.
5 ESB A bit in the Standard Event
Register has been set.
6 SRQ or MSS Value depends on the
polling method; see below
for details.
7 OPER A bit in the Operation
Status Register has been
set.
Bit 6 has two definitions, depending on how the access is polled:
• Serial Poll
If the value of the register is read using the serial poll (SPOLL), bit 6 is referred
to as the Service Request (SRQ) Bit. It is used to interrupt and inform the active
controller that the instrument has set the service request control line, SRQ.
3 Recommended Programming Techniques
28 Agilent J-BERT N4903B High-Performance Serial BERT
Bit 6