Watlow F4 Controller with LabView

[elew90]

Hello all,

I have a HX300 circulating chiller that uses a Watlow F4 controller. I want to control the F4 controller and monitor the conditions from it such as pressure rate and temperature using LabView. I heard of the Modbus driver that helps make this communication possible and have downloaded it. I am using the LabView 8.6 version and followed the necessary steps to include it into Labview. I have very little experience with Labview and am wondering how to begin writing the code for this. Any help is very much appreciated!

Thank you,

Eric

[Hooovahh]

Start here:

http://www.ni.com/gettingstarted/labviewbasics/

and here:

http://www.ni.com/academic/students/learn/

and here:

http://labviewwiki.org/LabVIEW_tutorial#External_Links

And if you have an active SSP here:

http://sine.ni.com/myni/self-paced-training/app/main.xhtml

After all of that open the Examples in the code you posted and see if they work.

[RTSLVU]

Modbus? Our Watlow F4 has a serial interface on it.

I guess yours could be different but regardless here is a link to a Watlow F4 Instrument Driver

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=E3B19B3E9722659CE034080020E748...

[elew90]

I noticed after looking through some posts by other people who are in the same situation, they seem to include a MB Serial Master Query.vi file. I couldn't find this in the modbus library. Is this a custom vi or is it found somewhere else in labview?

[elew90]

Never mind I found it.

RTSLVU,

I've seen threads where people used the modbus drivers to communicate with the watlow controllers. I should clarify. My setup is that I have a serial to USB adapter where the serial connection is at the controller's end and the USB connection is at the computer end. Should I be using the watlow driver or the modbus driver?

[RTSLVU]

It is possible that some of the systems with a Watlow F4 have a modbus interface.

But if yours has an RS232 serial interface then you will find it much much eaiser to use the Watlow instrument driver I linked to before and standard VISA serial comunications.

Your USB to Serial device should show up as a Com port in NI-Max if it is properly installed.

Download and install the Watlow instrument driver and you will find everything you need program the F4 including a couple programming examples.

[elew90]

I have a rs 422 serial interface. Is it still fine to use the watlow driver with this setup?

[RTSLVU]

In reality as long as your USB adaptor showes up in NI-MAX as a VISA device.

I think the Watlow insrument drivers will work.

[elew90]

So far I have gotten my chiller to be able to turn on and off but I get this error (see attached screenshot). I'm not sure what's wrong since it was working fine in the wlf4 profile example that came with the driver package. Most of the code was copied from the wlf4 example and modified to my code.

Also when I set the setpoint for the temperature it doesn't change. I think there might be a problem with the config files in the while loop?

I am using labview 2010 by the way.

[RTSLVU]

Since the error you are getting is a VISA timeout, the first thing you should try is increasing the timeout time (milliseconds).

Also PLEASE do not attach an image as an image pasted into Word document.

Use the Windows Snipping tool or your favorite screen capture tool and you can place the image in your post as I did.