Timeouts when using Watlow F4 drivers.

[john Brunn]

I've been struggling with erratic behavior using the Watlow F4 Labview drivers. I get timeout error messages at various times. I have verified the same hardware using Watlows Watview software. Everything ran fine using thier software. I am trying to integrate the Labview Watlow drivers with my Labview Application. Any help or tips would be appreciated.

[jjp377]

What VIs are you running when you see these errors?

[john Brunn]

The timeout errors occur in several VI's. I have used the "Watlow F4.lvlib:Read Alarm Status.vi" , "Watlow F4.lvlib:Read Analog Input.vi" and others. The error message is always the same "TIMEOUT".  It does work for a while. I have a loop running every second. It will fail after 8-12 iterations. I am using 19200 BAUD with the serial port.

I have tried this on two different machines with the same results. I have started to look into using the ActiveX feature of the Watview software with my Labview App. It appears to work

but I can't control the Watview update rate yet. I'll have to see if all the required parameters are visible to me.

I don't have to do anything fancy. I just have to monitor a ramp profile step and then after a soak of 30 minutes, I will execute my test procedure. I will then start another ramp step and soak cycle. This can continue for up to 10 cycles. I am fine with programming the profile using the watlow front panel controls. I just need to monitor the progress and then be able to start the next step in the profile or select a new profile. Since this is a long test, I need it to be reliable.

Thanks for any help or suggestions.

[Draicen]

I just went through the same issue in communicating with an F4D.  Try placing a 100 ms delay into the first "No error" frame of the Receive sub-vi.  I was able to run the program for 24 hours with a 1 sec scan rate without any further timeouts.

[john Brunn]

Thanks, I'll give that a try.

[Draicen]

My apologies, the specific vi is Watlow F4.lvlib:Utility MODBUS RTU Receive Message.vi

[john Brunn]

Excellent. It works great now. Thanks for the help.

[Oley Mich]

Hello!

Was there any more thought of pursuing the ActiveX route?

I'm interested in developing an application to interface with our Watview program.

The examples I have found don't really help me.

I'm ultimately looking to poll the Watlow input values via ActiveX and act on the values.

Thanks!

-Mark 

[john Brunn]

The ActiveX interface seemed to require more processor resources than the VI method. I didn't dig into it any further. The test system I was working with, already had a very elaborate Labview Test Application developed. I was affraid I would slow down the overall system if I persued the ActiveX route. Let me know how you make out?