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Appendix C: Status model
Model 2461 Interactive SourceMeter® Instrument Reference Manual
C-12
2461-901-01 A/November 2015
Status Byte Register diagram
The Status Byte Register consists of two 8-bit registers that control service requests, the Status Byte
Register and the Service Request Enable Register. These registers are shown in the following figure.
Figure 187: Model 2461 Status Byte Register
The bits in the Status Byte Register are described in the following table.
Bit
Decimal
value
Bit name
When set, indicates the following
has occurred:
0
1
Measurement summary Bit (MSB)
An enabled questionable event
1
2
Not used
Not applicable
2
4
Error available (EAV)
An error is present in the error queue
(warning and information messages do
not affect this bit)
3
8
Questionable summary bit (QSB)
An enabled questionable event
4
16
Message available (MAV)
A response message is present in the
output queue
5
32
Event summary bit (ESB)
An enabled standard event
6
64
Request for service (RQS)/Master summary
status (MSS)
An enabled summary bit of the Status
Byte Register is set; depending on
how it is used, this is either the
Request for Service (RQS) bit or the
Master Summary Status (MSS) bit
7
128
Operation summary bit (OSB)
An enabled operation event