Keysight E3633A, User Manual

Page: 132 / 205

4 Remote Interface Reference
132 Keysight E3633A and E3634A User’s Guide
The SCPI Status Registers
All SCPI instruments implement status registers in the same way. The status
system records various instrument conditions in three register groups: the Status
Byte register, the Standard Event register, and the Questionable Status register
groups. The status byte register records high-level summary information reported
in the other register groups. The diagram on the subsequent pages illustrates the
SCPI status system used by the power supply.
What is an event register?
An event register is a read-only register that reports defined conditions within the
power supply. Bits in an event register are latched . Once an event bit is set,
subsequent state changes are ignored. Bits in an event register are automatically
cleared by a query of that register (such as
*ESR?
or
STAT:QUES:EVEN?
) or by
sending the
*CLS
(clear status) command. A reset (
*RST
) or device clear will not
clear bits in event registers. Querying an event register returns a decimal value
which corresponds to the binary-weighted sum of all bits set in the register.
What is an enable register?
An enable register defines which bits in the corresponding event register are
logically ORed together to form a single summary bit. Enable registers are both
readable and writable. Querying an enable register will not clear it. The
*CLS
(clear
status) command does not clear enable registers but it does clear the bits in the
event registers. To enable bits in an enable register, you must write a decimal
value which corresponds to the binary-weighted sum of the bits you wish to
enable in the register.