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<== Date ==> | <== Thread ==> |
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Subject: | Re: Question about a tutorial wiritten by Norum |
From: | Eric Norum <[email protected]> |
To: | [email protected] |
Cc: | tech-talk <[email protected]> |
Date: | Tue, 30 Sep 2008 08:23:59 -0500 |
hi, all:
I want to write a driver for one of our serial devices, so I read "How to create EPICS device support for a simple serial or GPIB device". (http://www.aps.anl.gov/epics/modules/soft/asyn/R4-9/HowToDoSerial/tutorial.html )
While I have several questions: 1. in the tutorial, it said:
Command array index 0 – Device Reset
{&DSET_LO, GPIBWRITE, IB_Q_LOW, NULL, "\377\377\033", 10, 10,
NULL, 0, 0, NULL, NULL, "\033"},
I don't understand what's the meaning of "\377\377\033", does it mean "377" is oct number?
Yes. That's standard C syntax. If you prefer hexadecimal the equivalent would be "\xFF\xFF\x1B".
2. in function "convertPositionReply" and "convertStatusReply",
first time, pli->val = pdpvt->msg[0];
second time, pli->val = pdpvt->msg[1];
Does it mean the AB300's response data begin from different position? can anyone give me some explanation?
I have never used GPIB device before, so forgive my innocence. Thanks a lot in advance.
-- Eric Norum <[email protected]> Advanced Photon Source Argonne National Laboratory (630) 252-4793