Models 707B and 708B Switching Matrix Reference Manual
Appendix C: Status model
707B-901-01 Rev. A / August 2010
C-15
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
(on page C-16) describes the structure of these registers.
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
(on page C-16), a logical AND
operation is performed on the summary
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
Status byte and service request commands
(on page C-
