Connecting many Eurotherm 3216

[Ano Ano]

Hello,

I bought a 3216 controller, and I can communicate with the instrument just fine via the Labview drivers.

 

I am trying now to set the code in order to communicate with 10 controllers in series. I made a 10-iteration For Loop and in each loop it sends the iteration number to the controller as a unit id (by the way this works on Omron controllers). The aim is to get at the end of the For Loop and array with temperature values from all the controllers.

 

 

When it tries to read from the other controllers (which dont exist because I only have one) I get an error:

 

Warning 1073676294 occurred at VISA Read in Eurotherm 32xx Series.lvlib:Utility MODBUS RTU Receive Message.vi->Eurotherm 32xx Series.lvlib:Utility Read From Register - Floating Point.vi->Eurotherm 32xx Series.lvlib:Utility Read From Register - Float or Int.vi->Eurotherm 32xx Series.lvlib:Read Process Variables.vi->Eurotherm 3216 Read & Write v1.2.vi->Eurotherm 3216 Control & Monitoring v1.5.vi

Possible reason(s):
VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed.

 

 

I tried increasing the instrument timeout time but it did not solve the issue.

 

I am sensing that this may not be the optimum way to controll "Nth" controllers.

 

Does anyone have a suggestion?

 

Thank you in advance!

[todd]

So VISA read works when you read from an instrument that exists, and VISA read times out when you read from an instrument that doesn't exist? That sounds like expected behavior.

[Ano Ano]

Hello Todd,

 

Yes, it is expected, but when you have 10 controllers and 1 is switched off (closed or damadged), the code stops due to the timeone on this controller!

I would prefere if the code searched for a controller and if not found, return with a zero, instead of closing.

[todd]

Could you filter the timeout error when it occurs, and report the unit ID - perhaps in a warning?

[jtl]

Hello Ano Ano,

 

I'm having trouble communicating with my 3216 with the example code from the driver. In running both Process Value Monitoring and Temperature Control Monitoring, I received the same error message you did, though I'm simply trying to communicate with one device.

 

Error -1073807339 occurred at VISA Read in Eurotherm 32xx Series.lvlib:Utility MODBUS RTU Receive Message.vi->Eurotherm 32xx Series.lvlib:Utility Read From Register - Floating Point.vi->Eurotherm 32xx Series.lvlib:Utility Read From Register - Float or Int.vi->Eurotherm 32xx Series.lvlib:Read Process Variables.vi->Eurotherm 32xx Series Process Value Monitoring.vi

 

I'm not well versed in LabView, how does one determine the parameters to enter for Unit Address, Baud Rate, Parity, and Break Length? And would an error in entering these values result in the error that I experienced?

 

Thank you in advance

 

jtl