wtf4 rs232-USB

[DEPutman]

Change your search parameter from WTF4 to WLF4.  There is a plug and play driver available from NI for this device.  It is also important to note, communication with this controller is accomplished through simple register read and write operations; there is no SCPI command support.

You will need to get some programming / commissioning documentation from your equipment supplier for this controller.  While Watlow makes it, the equipment OEM is responsible for its operation, which included programming, they should have the information you need.

Dave

[SnowMule]

WTF4 or WLF4?  "WTF4" returns some interesting youtube videos in a google search.

The WLF4 is a Modbus controller, not SCPI.  Sending "*IDN?" to a Modbus device is like asking a question in English to someone who only speaks Russian.

There's already LabVIEW drivers for the WLF4 series controllers available, which takes the Modbus part (the worst part imo) out of the development process.

[tian66]

Hi Dennis,

I have got a password to unlock the watlow f4 of the espec chamber.

The baud reate is 9600 and the device number is 1 by default. I have set this in the MAX.

But I still have the timeout issue. I called the Watlow Controller company and they said the handshake is RTS/CTS. I tried that but I have no luck.

Do you have any furhter suggetion on this? Espec Support are not helpful, what they can tell is "rs232-usb  should work".

Thanks!

[RavensFan]

Did you confirm you are using the right type of cable?  (Straight through vs. null modem)

Have you tried communicating with any other software such as something Watlow might supply?

[tian66]

Hello Dennis,

Finally I got an answer from Espec. They said RS232 to USB will work.They suggest me to  try rs232 to ethernet.

I think this answer is a little weird since rs232 was tranfer to anther type of communication.

Anyway Thanks! 

[tian66]

Yes, I tired the Comm7 provided by watlow. It can read nothing from the controller.

Also please look at my latest reply.

Thanks!

[DennisKnutson]

You still have not confirmed that you are using the correct type of cable. Do NOT mention the USB-RS232 converter again. That is NOT what you have been asked to check.

[tian66]

I cannot 100% sure if it is the correct cable.

http://forums.ni.com/t5/LabVIEW/Watlow-F4-Communication-Cable/m-p/2511566#M764287

I got reply from both NI and Espec this cable should work. But fianlly Espec told it will not work.

What else can I check?

Thanks!

[tian66]

Thanks!

So you think this cable should work? and how can I test the connecttion?

[DennisKnutson]

What sort of basic research have you done on RS232? Between the instrument and the DB9 end of the convertor, there is a separate cable. It will either be a null'modem' or straight through type. Find out what you need and what you have. It requires nothing more complicated than an ohmmeter and a minute of your time.