Hello,

I have two (2) generators set using RS-485 Modbus RTU Slaves, that I will Integrate with my PLC which will be the Modbus Master. The problem is that the generator's slave address is 1, same for both devices, and I don't see any way to change the slave address in order to integrate them to my network.

I can communicate with both, but separate, not in the same network. (One at the time)

There is any way that I can Integrate both to my RS-485 Modbus RTU networks at the same time?

 

If there is no way to change the slave address and you only have a single Modbus master port then you will need some additional hardware to solve your problem. You could use our Omnii-Comm http://www.miille.com/din266-p00.pdf between your Master and the slaves. You would configure the Omnii-Comm to have two Modbus Master ports and a single Modbus Slave port. Data from each generator would be collected by the Omnii-Comm and placed into a common database. For example, data from generator #1 could be placed into holding registers from 1 to 255 and data from generator #2 into holding registers 1001 to 1255. Your master then reads and writes to the Omnii-Comm database as a single device. If you need additional information, you can contact us directly and miille.com.

Jerry Miille

 

I think the devices should have some DIAL SWITCH to define the adress,if else your devices does not support mult-communication

 

Hello Francisco;
On Modbus as on most bus configurations (actually I know of no exceptions), all elements of the network must be adapted with unique addresses. So if both you generators have "locked" Modbus addresses of 1, then you are scr***d, basically.
Now, you do not mention the type of generator you are integrating; but I have never seen a Modbus slave with only one address. There is always some mechanism, hardware or software, often in the unit's selectable parameters, through which you can change the Modbus communication parameters, including the Modbus address. Look for that in the units documentation, or contact a technical rep of the vendor.

Hope this helps,
Daniel chartier

 

To add on top of all that have already been said, I find it hard to believe that the generator manufacturer intended to shoot himself in the foot - not being able to sell more than ONE generator to any particular customer.

Meir