Remote Operation
SCPI Commands for Digital Interfaces
Release 3.0 155

Status Byte

The Status byte register contains the STB and RQS(MSS) messages as defined in 488.1. The user can read the status byte register using a 488.1 serial poll or the 488.2 *STB? common command. If the user sends a serial poll, bit 6 will respond with Request Service (RSQ). The value of the status byte is not altered by a serial poll.The *STB? query causes the device to send the contents of the Status Byte Register and the Master Summary Status (MSS) summary message. The *STB? query does not alter the status byte, MSS, or RQS.

Table 4.21Status Byte Summary Register

Error/Event Queue (ERR)

This bit it TRUE if any errors are present in the Error/Event Queue.
Bit Bit Weight Bit Name Description
01Reserved
12Reserved
2 4 Error/Event
Queue (ERR)
Set if any errors are present in
the Error/Event queue.
3 8 Questionable
Status Register
(QSR)
Set if any bits are set in the
Questionable Status Event
register.
4 16 Message
Available (MAV)
Indicates whether the output
queue is empty. MAV is TRUE
if the device is ready to accept
a request from the controller.
5 32 Standard Event
Status Bit
Summary (ESB)
A summary of the Standard
Event Status Register.
6 64 Request Service
(RQS)
Master Status
Summary (MSS)
MSS indicates that the device
has at least one reason for
requesting service.
7 128 Operation Status
Register (OSR)
Present if a bit is set in the
Operation status register.