KEPCO EL Series Electronic Load Operator Manual P/N 243-1295 Firmware Version 4.00 to 4.xx - Manual (Page 68)

A-4
SERIES EL 071414
A.10 *SRE — SERVICE REQUEST ENABLE COMMAND
*SRE
Syntax: *SRE where = value from 0 - 255 per Table A-3, except bit 6 cannot be pro-
grammed.
Description: Sets the condition of the Service Request Enable register. The Service Request Enable register
determines which events of the Status Byte Register are summed into the MSS (Master Status Sum-
mary) and RQS (Request for Service) bits. RQS is the service request bit that is cleared by a serial
poll, while MSS is not cleared when read. A “1” (1 = set = enable, 0 = reset = disable) in any Service
Request Enable register bit position enables the corresponding Status Byte bit to set the RQS and
MSS bits. All the enabled Service Request Enable register bits then are logically ORed to cause Bit 6
of the Status Byte Register (MSS/RQS) to be set.
A.11 *SRE? — SERVICE REQUEST ENABLE QUERY
*SRE?
Syntax: *SRE? Response: = value from 0 - 255 per Table A-3.
Description: Reads the Service Enable Register. Used to determine which events of the Status Byte Register are
programmed to cause the electronic load to generate a service request (1 = set = function enabled,
0 = reset = function disabled). Related Commands: *SRE, *STB?
A.12 *STB? — STATUS BYTE REGISTER QUERY
*STB?
Syntax: *STB? Response: value from 0 to 255 per Table A-3.
Description: Reads Status Byte Register without clearing it. This Query reads the Status Byte Register (bit 6 =
MSS) without clearing it (1 = set = function enabled, 0 = reset = function disabled). The register is
cleared only when subsequent action clears all set bits. MSS is set when the electronic load has one
or more reasons for requesting service. (A serial poll also reads the Status Byte Register, except that
bit 6 = RQS, not MSS; and RQS will be reset.)
A.13 *WAI — WAIT COMMAND
*WAI
Syntax: *WAI
Description: Causes the load to wait until all previously issued commands and queries are complete before execut-
ing subsequent commands or queries. This command can be used to guarantee sequential execution
of commands and queries. When all pending operations are complete (all previous commands have
been executed, the WAI command is completed and execution of subsequent commands can con-
tinue.
TABLE A-3. SERVICE REQUEST ENABLE AND STATUS BYTE REGISTER BITS
CONDITION OPER
MSS
RQS
ESB MAV QUES CSUM NU NU
BIT 7 6 5 4 3 2 1 0
VALUE 128 64 32 16 8 4 2 1
ESB Event Status Byte summary
MAV Message available
MSS Master Status Summary
NU (Not Used)
OPER Operation Status Summary
QUES QUEStionable Status Summary
RQS Request for Service