Responding To Parallel Polls - HP 9000 Series 300 Tutorials Manual
Device i/o and user interfacing hp-ux concepts and tutorials
Hide thumbs
Also See for HP 9000 Series 300:
- Owner's manual (162 pages) ,
- Hardware configuration manual (157 pages) ,
- Service handbook (108 pages)
Table of Contents
To determine which of these conditions caused the error, your program should
check for the following values of errno:
errno Value
EBADF
ENOTTY
Error Condition
eid does not refer to an open file.
eid does not refer to a raw interface file.
ETIMEDOUT A timeout occurred. (EIO on Series 300)
EACCES
The interface associated with this eid was locked
by
another process
and
O_NDELAY
was set for this eid.
Responding to Parallel Polls
Before the HP-IB interface on your computer can respond correctly to a
parallel poll from another Active Controller, the response must be configured
on the interface. This can be programmed remotely by the Active Controller as
discussed previously in the Active Controller section of this chapter, or locally
using hpib_card_ppoll_resp.
To configure a parallel-poll response:
• Specify the logic sense of the response (i.e. whether a 1 means the
device does or doesn't need service) .
• Specify which data line the device responds on. Two or more devices
can be configured to respond on a single line.
To locally configure response to parallel polls, call hpib_card_ppoll_resp as
follows:
where eid is the entity identifier of an open interface file and response is an
integer whose binary value configures the response.
Controlling the HP-IB Interface
3-61
- Quick Links:
- Variation between Computer Systems
Hide quick links:
Table of Contents
