mapping tags to modbus

Discussion of configuring and troubleshooting communication to PLC's or other devices using iX Developer.
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charliehbeijer
Posts: 40
Joined: Sat Jun 02, 2012 7:43 am

mapping tags to modbus

Post by charliehbeijer »

I have added a modicon modbus slave controller to my T7A project.

I'm sorry, I can't find the explanation how to map tags to modbus coils and registers. How is that mapping done?

Also, in the Tags screen of IXDeveloper, there is a column for each controller. The cells of the column contain a text field. What are those text fields for? Maybe they have something to do with the mapping?

mark.monroe
Posts: 824
Joined: Tue Mar 13, 2012 9:53 am

Re: mapping tags to modbus

Post by mark.monroe »

There is a forum post on where to find the help file for a give controller. The help file tells you how to map Modbus registers to tags.

The screenshot below tells you where you need to enter in the modbus address. Whether the address entered is hex or dec can be set in the controller driver.
Snap 2012-09-19 at 12.39.01.jpg
Snap 2012-09-19 at 12.39.01.jpg (32.11 KiB) Viewed 10461 times
Best Regards,
Mark Monroe

Beijer Electronics, Inc. | Applications Engineer

charliehbeijer
Posts: 40
Joined: Sat Jun 02, 2012 7:43 am

Re: mapping tags to modbus

Post by charliehbeijer »

I appreciate all your help, Mark. Don't know how I'd do this without you.

FYI, I read the help file Modbus Slave RTU/TCP. The information how to map tags is not in there.

mark.monroe
Posts: 824
Joined: Tue Mar 13, 2012 9:53 am

Re: mapping tags to modbus

Post by mark.monroe »

The circle in my previous post is around a modbus address. You type in the modbus address that you want associated with that tag in the Controller 1 column. You can also look at the Modbus Master help file, which gives you a little more info on what the different memory addresses mean. What they mean is defined by the Modbus protocol. You can look online for info on what the different memory addresses mean.

If a tag is a bit tag and you want it to be sent to register 40001.2, then you type in 40001.2 in the Controller 1 column. The Controller 1 column takes on the name of your controller. So your controller may be name "mycontroller", then the column would take on the same name.
Best Regards,
Mark Monroe

Beijer Electronics, Inc. | Applications Engineer

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