Modbus Communication Cable


Thread Starter

Chris Fisher

I cannot seem to find a run time cable diagram for communication between Magelis (XBTP021010) and TSX Micro (TSX 37/22) using MODBUS.

The reason for trying MODBUS is that the update time between Magelis and PLC is slow using UNITELWAY. I thought MODBUS have a faster update time or am I just dreaming.
The same cable that is used for Unitelway should work with Modbus, as both protocols work on the RS485 standard. Note: I have never tried
this. Also I do not believe that this will speed up the communication. If it is a graphical unit you may want to look at modbus plus. You
can also try arranging the registers into a continuous block which will possibly speed things up.
On TSX Micro default baud rate on TER port is 9600bds , you can increase it to 19200.

I don't think by using modbus the result will be twice better, you would have around 10% more but that's all I think.

Concerning data read into the PLC are there located into a concecutive area ? (This could be also a point to check)

Hope it helps

Best regards
Modbus is still only going to be 19200 baud. You're not going to make it any faster by going through the communication card on Modbus.

The cable you would need for the Modbus is the same one called out in the manual for communication with a Quantum PLC. All of the cable pinouts are in the manual or in the back of the catalog.

If you look for document 9001CT9802r3/00, which is the Modicon Magelis catalog, either on "": or "": under Automation Support, you will find pinouts on all of the communication cables in the back of the book. It's on page 38.::


Fernando Capelari - Schneider Brazil

You're right. The cable that you need does not exists. You have to assembly it.

Both Modbus and Unitelway runs at 19200bps at maximum. But the default is 9600. You have to define 19200 at the PL7 configuration window and at the XBTL1000 protocol parameters of your application (only for Modbus, for Unitelway the XBTL1000 windows does not matter, just for the XBT-F graphical models).

So, I think you should use Unitelway at 19200bps. There are many cables ready to use:
XBTZ968 - 2,5m
XBTZ9681 - 5m
XBTZ9686 - 16m