Event Status Register
The Event Status Register is an IEEE 488.2-defined register. The bits in this
register are latched. Once an event happens which sets a bit, that bit will
only be cleared if the register is read.
Service Request Enable Register
The Service Request Enable Register is an 8-bit register. Each bit enables
the corresponding bit in the status byte to cause a service request. The sixth
bit does not logically exist and is always returned as a zero. To read and
write to this register, use the *SRE? and *SRE commands.
Bit Definitions
The following mnemonics are used in figure 6-1 and in chapter 8, "Common
Commands":
MAV - message available
Indicates whether there is a response in the output queue.
ESB - event status bit
Indicates if any of the conditions in the Standard Event Status Register are
set and enabled.
MSS - master summary status
Indicates whether the device has a reason for requesting service. This bit is
returned for the *STB? query.
RQS - request service
Indicates if the device is requesting service. This bit is returned during a
serial poll. RQS will be set to 0 after being read via a serial poll (MSS is not
reset by *STB?).
Status Reporting
Event Status Register
6–4