Pinout Modbus TCP onto S7-1200 through profinet port

[BVG]

Hello All

I have a modbus tcp device(Julabo magio) with an DB9 pin assignment. Pin3=B and Pin8=A. I would like to connect it on the secondary port of a siemens PLC S71200 (X12). Now I was wondering which pin of the S71200 (RJ45 connector) i need to connect on the DB9 connector. My theory(after some google pictures):

A = +TX and +RX
B =-TX and -RX

S7-1200 port is full duplex;
Pin1:+TX
Pin4: -TX
Pin5: -RX
Pin6: +RX

So:
DB9.P8(A)= 1+6
DB9.P3(B)= 4+5

What do you think? i searched the siemens website but could find any pin layouts.

 

[mk42]

STOP before you try to wire them up more! Might break something.



Modbus TCP uses Ethernet, it's pretty much in the name. I've never seen Ethernet over DB9, although always a first time for everything.



If your device has a DB9 port, I strongly suspect it's good old serial modbus RTU. Can you post a link to the device?

 

[BVG]

No worries, wiring is for next week
But you are correct. I rechecked manual of the device. They just specify DB9 connector as a RS232/RS485 interface so it's indeed a good old modbus RTU. They also have an RJ45 ethernet interface for the modbus TCP/IP registers i guess. Was stuck into a manual rabbit hole. Ty for helping me out!

 

[sigmadelta]

You'll need to use a Modbus/TCP to Modbus RTU gateway, or put a RS-485 serial module on the S7-1200 and use the Modbus RTU master function block.

https://support.industry.siemens.co...rtal)-for-the-simatic-s7-1200-?dti=0&lc=en-BG

 

[the_msp]

You'll need to use a Modbus/TCP to Modbus RTU gateway, or put a RS-485 serial module on the S7-1200 and use the Modbus RTU master function block.

https://support.industry.siemens.co...rtal)-for-the-simatic-s7-1200-?dti=0&lc=en-BG

They also have an RJ45 ethernet interface for the modbus TCP/IP registers i guess.