Chapter 7
Programming in G Mode
© National Instruments Corp.
7-11
GPIB-232CT User Manual
Serial Poll
The GPIB-232CT will respond to a serial poll of the serial device by
placing a serial poll response byte on the data lines.
Table 7-7 contains the meanings of the bits in the serial poll response byte.
Table 7-7. Serial Poll Response Byte
!
Bit
Mnemonic
Meaning
!
!
0
—
Not
Used
!
!
1
BF
Serial port receive buffer is full
!
!
2
GERR
GPIB error - EARG, ECAP, ECMD
!
!
3
SERR
Serial error - EPAR, EORN, EFRM
!
!
4
BNE
Serial port receive buffer not empty and
serial device not addressed to talk
!
!
5
EOS
EOS character received and GPIB-232CT
not addressed to talk
!
!
6
RSV
Request
service
!
!
7
—
Not
Used
!
Service Request
The GPIB-232CT can be programmed to assert Service Request (SRQ) in a
variety of cases. After power-on, the GPIB-232CT defaults to never
asserting service request. You can program the GPIB-232CT to assert SRQ
under the following circumstances:
•
When the GPIB-232CT serial port receive buffer is full.
•
When a GPIB-error occurs, that is, EARG, ECMD, or ECAP as
reported by
stat
.
