S Mode Functions
Chapter 5
GPIB-SCSI-A User Manual
5-56
© National Instruments Corp.
pct - Pass Control
Type:
Specialized Controller function
Purpose:
Use
pct
to pass Controller-In-Charge (CIC) authority from
the GPIB-SCSI-A to some other device.
Format:
Bit
7
6
5
4
3
2
1
0
Byte
0
Opcode = CCH
1
GPIB Primary Address
Reserved
2
GPIB Secondary Addr. (Opt.)
Mode Reserved
3
Reserved
4
Reserved
5
Reserved
Remarks:
If you call
pct
and the GPIB-SCSI-A is not Controller-In-
Charge (CIC), the GPIB-SCSI-A records the ECIC error,
issues a CHECK CONDITION status response, and sets the
Sense Key to ERROR.
If Mode is 0 and there is anything in the GPIB Secondary
Address, the GPIB-SCSI-A aborts the command, issues a
CHECK CONDITION status response, and sets the Sense Key
to ILLEGAL REQUEST.
The information transfer phases that the GPIB-SCSI-A drives
the SCSI through after selection are the Command, Status, and
Message In phases.
