Controlling a Watlow F4

[Naim876]

Hello All,

I am new to Labview and will be using it to communicate with a Watlow F4 controller. The instrument I am communicating with is a Watlow F4 controller used to control a Associated Enviormental Systems chamber. First, I would like to open a communiation to the controller and have it send data every 20 mins while I conduct my experiments. The chamber sends out information about temperature and humidity. I would like to record this as an excel file. Eventually I would like to set temperature/humidity profiles from labview and record the data.

Right now I have not been able to establish a successful communciation. I have been searching through similar threads but I'm still getting a timeout error. I have attached my current VI and appreciate any advice as I continue to troubleshoot my VI. 

Best,

Naim876

[James_Battleaxe]

Hi,

Could you try to use the *IDN? command through the VISA test panel in MAX? This is a good way to test if any sort of commands are getting through to your controller.

[Dennis_Knutson]

I believe the F4 uses modbus and sending idn would just be silly.

Naim,

I'm posting by phone so I can't view your VI. Which modus driver are you using?

[Naim876]

That is correct, It uses Modbus. I first attempted using the Waltlow drivers but they didnt to work so I substiuted the serial-visa. Take a look at the VI when you get a chance and let me know. All help is valued, thanks.

Naim

[Dennis_Knutson]

As I said, I'm posting from my phone. Attach a snippet of the block diagram. The VISA functions by themselves are not enough. You should be using the modus library.

[Naim876]

see attahced snippet

[Dennis_Knutson]

That's not a LabVIEW snippet. Look it up in the help.

You aren't using the modbus library. I said you couldn't use the plain VISA functions. You could have done the search yourself -
http://www.ni.com/example/29756/en/ 

[Naim876]

I am running an old version of Labview, verson 8. 

[Dennis_Knutson]

Upgrade LabVIEW or request a down conversion. The conversion board is linked at the top of the main LabVIEW c page.

[adina25]

I had a similar timeout problem with a Watlow controller because I wasn't setting the right baud rate. Mine required 19200.

Once I set that right, the communication was ok.

Later edit: 19200, not 19600 I initially wrote.