Register Programming Example; Status Byte And Service Request (Srq; Service Request Enable Register - Keithley 708B Reference Manual

Models 707B and 708B Switching Matrix Reference Manual

Register programming example

The command sequence below programs the instrument to generate an SRQ and set the system
summary bit in all TSP-Link nodes when the thermal aspect bit of a card in slot 1 is set:
-- Clear all registers.
status.reset()
-- Enable SLOT1_THERMAL bit in questionable register.
status.questionable.enable = status.questionable.SLOT1_THERMAL
-- Set the system summary node QSB enable bit.
status.node_enable = status.QSB
-- Set the QSB bit of the service request enable register.
status.request_enable = status.QSB

Status byte and service request (SRQ)

Two 8-bit registers control Service request: the Status Byte Register and the Service Request Enable
Register. The

Service request enable register

The Service Request Enable Register controls the generation of a service request. This register is
programmed by the user and is used to enable or disable the setting of Bit B6 (RQS/MSS) by the
Status Summary Message bits (B0, B1, B2, B3, B4, B5, and B7) of the Status Byte Register. As
shown in Status byte register
bits (&) with the corresponding enable bits of the Service Request Enable Register. When a logical
AND operation is performed with a set summary bit (1) and with an enabled bit (1) of the enable
register, the logic "1" output is applied to the input of the logical OR gate and, therefore, sets the
MSS/RQS bit in the Status Byte register.
The individual bits of the Service Request Enable register can be set or cleared by using the *SRE
common command or status.request_enable. To read the Service Request Enable register, use
the *SRE? query or print(status.request.enable). The Service Request Enable register
clears when power is cycled or a parameter value of 0 is sent with a status request enable command
(for example, a *SRE 0 or status.request_enable = 0 is sent). The commands to program and
read the SRQ Enable register are listed in
18).
707B-901-01 Rev. A / August 2010
Status byte register (on page C-16) describes the structure of these registers.
(on page C-16), a logical AND operation is performed on the summary
Status byte and service request commands
Appendix C: Status model
(on page C-
C-15