DEAR SIR, I M TRYING TO COMMUNICATE WITH EUROTHERM 2640 CONTROLLER THROUGH NI PCI 8431/8 PORT RS 485 INTERFACE BUT NOT ABLE TO ESTABLISH THE COMMUINACTION . THE PROTOCOL IS MODBUS AND INTERFACE IS EIA RS 485 ( 2 WIRE) ,NULL MODEM CABLE( CROSS CABLE). FOR COMMUNICATING I HAVE SORTED THE TX + AND RX + AND TX- RX- . I HAVE TRIED NI MODBUS LIBRARY FOR COMMUNICATING BUT NOT ABLE TO DO THE SAME. ON SEARCHING THIS FORUM I CAME TO KNOW ABOUT THE OPC CONNECTIVTY IS POSSIBLE. I M TOTALLY CONFUSED DONT KNOW HOW TO PROCEED.
Can you give a link to your device's documentation? Also, some Modbus devices come with a display that indicates when a connection with the controller is successfully established. Does your device have such an indicator? If yes, then you need to check the connection status before proceeding with the coding.
Were you trying to run a specific example for Modbus comunication? Can you post a link to the code, or attach your own code if that is what you're trying?
Thanks for your reply. Attached is the Manual of controller(eurotherm 2604) communication on 485( 2wire). for communicating. The eurotherm has got a display in the front along with the programmable keys for programme. I m using modbus libraray to view the data.
while browsing through the manufacturer website i found that there are two ways through which we can commuinacte with the controller 1) digital commuincation on modbus 2) opc link to labview.below is the link where i saw:- http://www.eurotherm.com.au/control/product/x26.htm . The Product link is given below:- http://www.eurotherm.com.au/control/product/2604.htm
kindly suggest how to proceed
Effectively, you can use ModBus or OPC to control 2604 regulator.
The simplest way is to setup and to use iTools (& so iTolls OPC Server) provided by Eurotherm. The evaluation version is sufficient.
With iTools, you can get OPC syntaxes and/or ModBus Addresses and reuse information with LabVIEW.
To use the 2604 regulator with OPC server, use the DataSocket VIs (in Data Communication palette). Get the URL with iTools Enginneering Studio by selecting a property, then right click and select 'Copy the parameter'. The URL could be reused in labVIEW as OPC address.
To use 2604 regulator with ModBus, I use our own ModBus driver but the principle is the same in LabVIEW. Check the addresses in the dedicated column from iTools Engineering Studio. For example, get PV to address '1', set W_SP to address '5', etc...
hi, I refresh thread
i need control device with et2604
output device has label rs-422
i have card moxa cp 132 which has 2 ports
first set rs-485 (via this port I control et3208 with any problems) second set rs-422
iTools eurotherm unfortunately show only et3208
where is the problem?
Hello All. I have problem with eurotherm 2604 too.
I cant set SETpoint, I can read data, but if i want to change Programmer/Timer Status it fail on register write.
It fails same way with 24xx and 32xx LV drivers.. I dont have idea what's wrong with it.