Reading The Status Byte Register; Clearing The Status Byte Register - Tabor Electronics 5064 User Manual

Reading the Status
Byte Register
Clearing the Status
Byte Register
5-76
Bit 2 - Decimal value 4. Not used, always set to 0.
Bit 3 - Decimal value 8. Not used, always set to 0.
Bit 4 - Decimal value 16. Message Available Queue Summary
Message (MAV). The state of this bit indicates whether or not the
output queue is empty. The MAV summary message is true
when the output queue is not empty. This message is used to
synchronize information exchange with the controller. The
controller can, for example, send a query command to the device
and then wait for MAV to become true. If an application program
begins a read operation of the output queue without first
checking for MAV, all system bus activity is held up until the
device responds.
Bit 5 - Decimal value 32. Standard Event Status Bit (ESB)
Summary Message. This bit indicates whether or not one or
more of the enabled ESB events have occurred since the last
reading or clearing of the Standard Event Status Register.
Bit 6 - Decimal
(MSS)/Request Service (RQS) Bit. This bit indicates if the device
has at least one condition to request service. The MSS bit is not
part of the IEEE-STD-488.1 status byte and will not be sent in
response to a serial poll. However, the RQS bit, if set, will be
sent in response
Bit 7 - Decimal value 128. Not used, always set to 0.
The Status Byte summary register can be read with the *STB?
common query. The *STB? common query causes the generator to
send the contents of the Status Byte register and the MSS (Master
Summary Status) summary message as a single <NR1 Numeric
Response Message> element. The response represents the sum of
the binary-weighted values of the Status Byte Register. The *STB?
common query does not alter the status byte.
Removing the reasons for service from Auxiliary Status registers
can clear the entire Status Byte register. Sending the *CLS
command to the device after a SCPI command terminator and
before a Query clears the Standard Event Status Register and
clears the output queue of any unread messages. With the output
queue empty, the MAV summary message is set to FALSE.
Methods of clearing other auxiliary status registers are discussed in
the following paragraphs.
value 64. Master
to a
Summary Status
serial poll.