Modbus Adress from otg file

Hello Dear Forum

in my .net application i’m accessing SNAP pack EB1 thought modbus since i will have a lot of migration to do, i whiling to make a tool to import acquisition rack configuration to my app using otg file.
for DIN and DOUT there is the module and channel number that allow me to guess modbus adress
but not for AIN/OUT

so my question is there a way to guess analogic modbus adresse from and otg file? or is there a better way ?

Best regards

There is a better way.

Use PAC Manager.

First, do an inspect of the EB1 to view the AIN/AOUT.

Once you have the memory map address of the analog point you want, then use the Modbus calculator in PAC Manager to resolve the Mobus address of your AIN/AOUT.


Here you can see the same MMP address from the unit in the calculator.

And so now we know the Modbus address of that analog point.

Ok i was kowning this one, it require that you have acces to the plc (so no work from desk)

but i’m trying to find a way programmatically do it, to do that before going to the production site to avoid wasting time for my customer :wink:

i have more that 30 rack to process i will really gain a lot of time if i can make a tool :wink:

@bferlicot have you checked out the C++ or Python OptoMMP libraries?
They have to be able to calculate these memory addresses, so the math they use might be able to solve your problem too.

The OptoMMP protocol guide goes into even more detail, but basically once you know the base address and module / channel offsets it should be just one line of math to find the exact memory address – something like this:

AIN = 0xF0260000 + (module * 0x00001000) + (channel * 0x00000040)

Once you have found the Opto memory address just follow the conversion steps described by the Modbus calculator and you should have your unit ID and register for any given module / channel.

thanks i have finish by finding a way, our new service (shit) based Excel was removing last field of the otg file.

so i can guess modbus adress using module/channel number thanks for your help.

this is saving me a lot of unpleasant work :wink: