Running two Eurotherm 3216 temperature controllers using the driver available from Labview

[Mauricio.]

Hi All,

I am trying to control two Eurotherm 3216 temperature controllers using the driver provided by NI at http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=7F14CDCB24923797E04400144F1EF8.... Specifically, I am using the "Temperature Control Monitoring" example.

I have been able to operate a single temperature controller using this code. However, I need to operate two controllers, and I havent been able to modify the code appropriately to do it.

I initially tried just repoducing the entire code and running it but that provides me with an error. However, if I run the code while using "highlight execution" it works just as I need it to...except to slowly for my purpose.

If anyone has any insight as to how I may run both controllers, I would really appreciate it.

Thanks

[nyc_(is_out_of_here)]

The driver looks as if it uses serial interface.

Do you have two serial ports you can use?

[Mauricio.]

We do have more than one serial port but there is a special converter (KD485-ADE; converts RS485 --> RS232) that needs to be used with each Eurotherm controller if they are to be connected to separate serial ports. Plus, the purpose of the adapter is to be able to run up to 32 devices through the same port.

We did manage to run the other example code given by LabView NI, labeled "process value monitoring", with both controllers hooked up and it worked fine. All we did was duplicate the code and change the adress for each device just as we tried for the other code.

Again, thank you for any help

[nyc_(is_out_of_here)]

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@Mauricio. wrote:

We do have more than one serial port but there is a special converter (KD485-ADE; converts RS485 --> RS232) that needs to be used with each Eurotherm controller if they are to be connected to separate serial ports. Plus, the purpose of the adapter is to be able to run up to 32 devices through the same port.

We did manage to run the other example code given by LabView NI, labeled "process value monitoring", with both controllers hooked up and it worked fine. All we did was duplicate the code and change the adress for each device just as we tried for the other code.

Again, thank you for any help

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After that long explanation, I still don't know how many serial ports you are using.

[Mauricio.]

We have more than one serial port available but we are currently only using one since that is the way that is indicated on the respective installation guide. I have attached this guide and the wiring diagram describing my setup is shown on page 16.

Thanks again for your help.  

[d_n]

It is not clear what type of communication boards the 3216 controllers have.

If they have RS232 boards installed then you will have problems because RS232 does not support multiple devices. If on the other hand they have RS485 comms boards installed then yes you can connect the 2 controllers to one Serial ComPort via the KD485 converter.

What Error are you getting when you are running the code in full speed?

[d_n]

Here something’s to try.

1)      Make sure both controllers have RS485 comms modules installed

2)      Connect both controllers in Daisy Chain configuration using the EIA485 instructions from Page 16 of the Manual you mentioned.

3)      Ensure both the KD458 and the 3216 controllers have identical  Comms configurations. ie Baud Rate, Parity etc

4)      Verify your setup:  In the "Temperature Control Monitoring" example” change the Unit Address, Baud Rate, Parity and Break Length  to match the 1^st controllers values. Verify that you can communicate with the 1^st controller.

5)      Using the Same "Temperature Control Monitoring" example”, NOT a second copy, change the Unit Address, Baud Rate, Parity and Break Length to match the 2^nd controllers values. Verify that you can communicate with the 2^nd controller.

Comms problems are difficult to fault find so be methodical and you will succeed.

[DanColoS]

Hey guys,

  I am also trying to operate two Eurotherm 3216's as well as a 3508 in the same fashion, daisy chained and same driver.  However, mine will connect and work shortly and then kick me back a "-1074001422" error.  The 3508 works great with the 3508 driver.  Also, I can opperate all three controllers through Eurotherm iTools which tells me everything is wired correctly.  My only problem is with operating the 3216’s with the Labview Driver.   I have matched all of the comm configurations but still keep getting the error.

Any ideas?

[d_n]

What operation you are performing when you get the Error. Reading or writing parameters?  It is difficult to assist without further details. Can you publish or send me the code you are using. I am using Labview 8.21

It is very frustrating when members of the Labview community try to help and the originator of the post does not bother to return and give feedback if any of the suggestions helped to solve the problem and how it was solved. Very Unprofessional.

[DanColoS]

So I did A LOT of probing on this today.

The error originates in the "Utility Modbus RTU Receive Message" subvi.  It occurs when some bits read do not equal to a "CRC" value from another VI.  Not quite sure what that is.  
There is a framing error(-107380725) that occurs in the same VI but does not seem to coincide with when the -1074001422 initiates.