100
8-9-4. Reading data from the status byte and clearing the status byte
Data of the status byte may be read out from the controller in the
following two ways:
・
Inquiry with the
＊
STB? query
When an inquiry is made with the
＊
STB? query, MSS is read out of bit 6.
No bits of the status byte are cleared after reading it.
・
Serial polling
When serial polling is executed, RQS is read out of bit 6. RQS
is only cleared after reading it. It is impossible to read MSS.
It is impossible to clear the status byte directly. It is necessary to clear
the event register or the like that is the cause of the status byte.
・
When ESB occurs
When an inquiry is made with
＊
ESR?, data of the standard event
register are read out and all bits are cleared then.
・
When the
＊
CLS command is received.
When receiving the
＊
CLS command, the PSF Series power supply
unit clears the standard event register and status byte.
・
When MAV occurs
The MAV bit is cleared when data are read out from the output
queue completely.
The output queue is not cleared by the
＊
CLS command.
When the event register and MAV are cleared completely, MSS in bit
6 is also cleared.
