Serial .DLL

[pete_dunham]

I downloaded a wrapper/.dll from NI’s Instrument Driver Network (uncertified).

http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=16725

for a Watlow integrated controller (EZ-ZONE PM) .

It works okay for the most part. However, every once and awhile, and seemingly for no reason, the calling VI crashes.

Not only does it crash, it locks up LabVIEW 2010 and Windows 7. Nothing works to close LabVIEW except for a system reboot.

(Sometimes it runs all day with no problems).

I am scratching my head to troubleshoot at a lower level. And/or identifying an alternative path. I haven’t had much experience troubleshooting .dlls at this level from LabVIEW.

I plan to install LabVIEW 2010 SP1 to see if that helps, but have a feeling it is the .dll causing the problem.

Has anybody else worked through something similar?

[MikaelH]

I use Watlow controller as well, but I've written my own rs232 drivers for it. I'm not sure if controller has the same register but this is an image of how my SetTemperature.vi looks like:

Cheers,

Mikael

[Jordan Kuehn]

Here are my get/set temperature vi's for a Watlow F4 controller. You also need the NI Modbus library.

And there seems to be an issue with the VI snippet. The clusters constants there can be remade and should have RTU and 1 as the values in them.

Hopefully this is of some help to you.

Edited February 23, 2011 by jkuehn

[pete_dunham]

Here are my get/set temperature vi's for a Watlow F4 controller. You also need the NI Modbus library.

And there seems to be an issue with the VI snippet. The clusters constants there can be remade and should have RTU and 1 as the values in them.

Hopefully this is of some help to you.

This is a late reply..but THANK YOU!

The NI Modus Library was exactly what I needed to solve this problem. And the attached snippets are what made this a clear solution.

For anyone else using Watlow .dll, downloaded from the NI Instrument Driver Network, this .dll (what Watlow refers to as "standard bus") seems to be the culprit. IE, the communication across this standard bus seems to be what is locking up my system.

The Watlow PM EZ-Zone I am working with has an optional RS232 Modbus module (determined by the controller’s serial number).

I switched from communicating from Watlow's standard bus to the Modbus and now my communications and LabVIEW seem stable.

Thanks again!