compact field point RLY 421

[nals]

Hi,

I am using cFP RLY 421 for switching relay.

The software application has been developed in VC++ using Measurement Studio 7.0.

And I am using datasocket.

The problem is following:

The channel is not updated although no error in syncwrite is returned.

On the same module other channel is updated.

This misbehaviour random.

How can I ensure that the channel has been updated.

Please help me out.

Thanks in advance.

regards

[Ching_F.]

Hello nals,

You can check the state of your cFP-RLY-421 module by using Measurement & Automation Explorer (MAX).  Open MAX, expand Remote Systems, find your cFP target, right click on the target and select Find Devices.  You will be prompted to name your controller.  Do so and then click ok.  Your cFP system will then appear under My System >> Data Neighborhood >> FieldPoint Items.  If you expand your cFP system you will see your cFP-RLY-421 module.  Click on the module, and click the Start button in the panel that appears to the right of the Data Neighborhood tree.  This will give you the state of all the channels on your cFP-RLY-421 module. 

If you notice through MAX that this channel has not been updated correctly, you can also try to write a value to that channel though MAX as well.  To do so, click on the channel, and then click on the Write button in the toolbar.  Now write either a 0 or 1 to the channel and see if you can change the state of the module through MAX.  If you are able to do so, there is most likely something in your code that is preventing the write.  If even through MAX you are unable to change the state of the channel, you may want to speak with an Applications Engineer who can help you troubleshoot over the phone.  You can visit www.ni.com/ask to create a service request.

Please let me know if you have any other questions or concerns.

Message Edited by Ching P. on 10-10-2007 02:43 PM

[nals]

We have checked this behaviour in Measurment and Automation explorer.
It works fine there.

Even our software code works fine mostly.
The problem occurs only once in a while.
When the problem occurs no error is returned by the syncwrite function call.
We do not know whether same API is used by M&A explorer.

[Wayne.C]

nals,

Can you describe setup a bit more?  What voltage relay are you controling with RLY-421?  Where is power for that relay coming from?  Have you installed any sort of snubber across the coil of the external relay?

[Eric A.]

Hi,
Could you explain more about how you know that your channels are not being updated?  If you elaborate more on your system then we have a much better chance of understanding what the problem might be.