99
8-9-3. function of the status byte
If some event occurs and some bit of the status byte is set to 1, bit 6 is
set to 1 and a service request (SRQ) is issued. Four status bits shown
below may possibly be the causes of an SRQ in the PSF Series power
supply unit.
Bit 5
ESB
Standard event status register summary
Bit 4
MAV
Message available
Bit 1
LERR
Local bus execution error
Bit 0
TMO
Local bus time-out
If an execution error occurs, bit 4 of the standard event status register
(ESR) is set to 1. When AND of the ESR and standard event status
enable register (ESE) is 1, bit 5 (ESB) of the status byte is set to 1. If
bit 5 of the service request enable register (SRE) is 1 at this time, bit 6
(MSS) of the status byte is set to 1 and a service request (SRQ) is sent
to the controller.
NOTE: An SRQ is issued through the GP-IB interface only.
