Specifications

M550129-03 Rev G 8-3
Various fault
events must be
enabled by the
protection
enable register
before they are
recorded in the
fault register.
Bit Hex Value Description
0 0x01 Constant Voltage Operation
1 0x02 Constant Current Operation
2 0x04 Converter Fault
3 0x08 Overvoltage Protection Fault
4 0x10 Over Temperature Fault
5 0x20 External Shutdown
6 0x40 Foldback Mode Operation
7 0x80 Remote Programming Error
Fault Register (also called the Protection Event Register).
Readable using the STAT:PROT:EVEN? query
The SCPI Status Byte. Read using either the *STB? command, or
the GPIB serial poll operation.
Bit Hex Value Description
0 0x01 Operation Complete
1 0x02 Request Control (Not Used)
2 0x04 Query Error (Not Used)
3 0x08 Device Dependent Error
4 0x10 Execution Error (e.g., range error)
5 0x20 Command Error (e.g., syntax
error)
6 0x40 User Request (Not Used)
7 0x80 Power On
Bit Hex Value Description
0 0x01 Not Used
1 0x02 Protection Event Flag
2 0x04 Error/Event Queue Message Avail.
3 0x08 Questionable Status (Not Used)
4 0x10 Message Available
5 0x20 Standard Event Status Register
6 0x40 RQS/MSS Service Request Bit
7 0x80 Operation Status Flag (Not Used)
Various
events set
the SESR
bits directly.
The SESR (Standard Event Service Register). Masking does not prevent events from
setting bits in the SESR. This facilitates polling as one means of detecting these events
since the SESR can be polled (read) using the *ESR? command, irrespective of the bits
set or not set in the Standard Event Status Enable Register.
The SESER (Standard Event Status Enable Register). This register is read
using the *ESE? SCPI query command. This register is written to using the
*ESE <value> command. A “1” in the appropriate bit location enables that
corresponding bit from the SESR to pass through to the input of the OR gate
to be included in the SESR summary bit (bit 5) in the SCPI Status Byte.
The Service Request Enable Register (SRER).
Used to enable which Status Byte bits can affect the
service re
q
uest bit. *SRE? reads. *SRE <value> writes.
Seven bit wise logical AND operations
Eight bit wise logical
A
ND operations
The Protection Enable Register. Readable using the STAT:PROT:ENAB? query command. Write-able using the STAT:PROT:ENAB <value>
command. Used to select what fault events may set a bit in the Fault Register. Certain faults can occur even if they are not enabled. This is
because the Protection Enable Register merely filters which events are allowed to affect the Fault Register, not whether those events can
occur or not. An exception to this rule involves the Constant Voltage Operation, Constant Current Operation, and Foldback Mode Operation
bits. If these bits are not enabled, then mode changes shall not cause a shutdown. Read about these bits further in the manual.
SCPI STATUS IMPLEMENTATION