I am trying to write a driver for the Watlow series 96. Any avaliable help?

[Laurie]

I was looking for an example VI to test communication between Labview 6.1 out the serial port to a series of Watlow 96 temperature controllers. I downloaded this library and found the vis in it to be very helpful. I did have to make one correction to the version that I received. In the Set Temperature vi the address input was not wired to all of the appropriate subvi's. So when I changed my Modbus address on my controllers to anything other than the default of one, I received a communication error. I completed the wiring and then it worked fine.

[drewtreb]

I need to read process and write setpoint to a Watlow Series 96.  Both process and setpoint can be negative (celsius).  I am connected through the PC's serial port.  I tried to use the Melcor.llb which I found on ni.com.  It works, but won't read or write negative numbers.  All the variables are unsigned.  I saw Brian's example Watlow.llb.  Will it handle negative readings?  Is it possible to transmit negative numbers over Modbus? 

[unclebump]

Modbus registers can be read as signed or unsigned and floating point. You could try using an opc server to talk to the device. Modbus just executes a read register command. The sign interpretation is done at each end.

Do you have this package??  http://www.watlow.com/products/software/watconnect.cfm

http://watlow.com/literature/prodtechinfo/files/controllers/series_96_um_rev.g_07-13.pdf

[mrp1409]

I have a Watlow series 96 temperature controller that has the ramping software option on it.  I've used brian vibert's drivers to try to communicate with it but to no avail.  In talking with watlow the ramping software had different addresses  than the standard software so I downloaded the tag files from watlow and compared but could not come to any conclusions.  Does anyone have an idea on  how i can communicate with the 96 series?

[Uri-Vyyo]

Hi Brian,

I'm using yours WATSetTemp.vi to set my temperature chamber to -30 - +60 oC (10oC steps).

In some cases, the WATLOW 96 controller is stacked in 0 oC (for example) and doesn't react to the setpoint.vi.

No error appears.

What can be the problem?

Uri.