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VRf-Error 814 Lock Acq Fail

Question asked by VRFuser on Apr 6, 1997
> To: VEE Reflector
> From: Peter Fender
> Subj: Error#814 Lock Acquisition fails
> Date: 07 Apr 1997
> Hello all,
> What does Error #814, "Lock Acquisition Failed on HP-IB interface hpib7" =
> mean ?  I could not find any details in either the manuals or online =
> help.

There is a software lock capability for SICL so that if multiple applications
attempt to access the same interface, only one will be able to do it and the
others will be locked out.

> We have a test system that is controlled either by an older HP computer =
> using HP BASIC (for older tests), or by a Windows PC using VEE 3.12 (for =
> current and future work).
> One of the two computers is selected using an HP-IB A/B switch to connect =
> the computer to about 8 instruments.
> I use Direct I/O for the instruments, but apparently the error occurs =
> before the first transaction. 

Does the error always occur?  If not, do you have some idea of the
circumstances under which it does occur?  Generally this happens when two
applications on the same PC try to access the same HPIB and one fails in
an uncontrolled fashion.

We have had cases long ago where if you had one application that failed (with
a timeout), the lock would remain and when you tried to access it again you
would get lock acquisition failed.  But I recall this was on RS-232 only.

> The VEE error occurs after some tests are done using the BASIC computer, =
> then the instruments switched to the PC.
> The only way I have been able to clear the error is to power down ALL the =
> instruments AND the PC, and restart.
> If just the instruments are turned off and/or disconnected, the error =
> remains.
> I would like to be able to clear the condition without cycling power on =
> the PC, then I can isolate which instrument is the source of the problem.

I am not certain that an instrument is the cause of the problem.

> Thanks in advance,
> Peter Fender
> Raytheon E-Systems, Inc.
> PO Box 12248
> St. Petersburg, FL  33733

Please stay in touch.

[<>] regards -- gvg