AnsweredAssumed Answered

VRF-Serial comms.

Question asked by VRFuser on May 13, 1998

Mark Stasik wrote:

> Hi,
> I am attempting to serially control a Watlow series 942 Thermal chamber
> controller. I am able to send commands to the controller, which are
> obeyed, but when I make a query for data, the instrument times out. I
> tried using an old DOS program obtained from watlow and it communicates
> bidirectionally perfectly. I checked all the communication settings of
> the instrument and both my VEE and DOS programs. All settings concur.
> Why won't VEE see the data being returned by the controller? Any ideas
> appreciated.

Im assuming you are using Direct I/O. I have sometimes found that altering
the "Read Terminator" sequence under device configuration makes the

You could also try using the Bus I/O Monitor. This will show you what is
actually being transferred on the serial interface, and you might be able
to adjust your device settings accordingly.

Kind regards,

John Sletten
Independent Consultant, Norway.