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Communication between a CommandHMI and a Schneider-Modicon TM221 M221 Twido TSX-37 Micro TSX-57 Premium PLCs

Wirring from the HMI to the RS485…

RJ45 plug of a TM221 M221 Twido

TER plug of NEZA TWIDO M218
TSX-37 Micro TSX-57 Premium

The operation of the TER (and AUX) socket depends on two parameters:

  • the software configuration of channel 0 defined under PL7 Micro/Junior/Pro
  • the signal status of the DPT pin of the TER connector

Therefore, for communication in Modbus protocol it is necessary to:

  • select ModBus/JBUS link in the PL7 configuration of channel 0
  • connect the DPT pin (pin 5) of the TER socket to 0V (pin 7)
COM1 or COM2
8 TX – <> 2 TX –
9 TX + <> 1 TX +
5 GND <> 7 GND

The distance HMI<>PLC must be less than 10 m

Important note concerning only the terminal port (mini DIN socket integrated in the Twido) :

The /DPT signal status (Pin 5) of the Mini DIN socket of the terminal port of the Twido allows or not the software configuration of this port described above to be taken into account:

  • /DPT signal not connected: The communication parameters of the terminal port (port 1) are fixed at 19200 bauds, 8 bits, 1 stop bit, no parity, Modbus RTU protocol, slave address 1.
  • Signal /DPT connected to 0V (Pin 7): The configuration of port 1 defined in the TwidoSuite application is taken into account by the Twido.

Therefore, in order for the parameters configured in TwidoSuite to be taken into account, it is necessary to connect the /DPT signal (pin 5) to 0V (pin 7).

SoMachine configuration

PL7 configuration

HMI-Tool configuration

Choose RS485 (Extended mode)

Communication port properties: Modbus RTU Master

Address entry: We use 4x and 0x

  • To access the Boolean memory (like %M1 or %M2), enter an address like “0x1” or “0x2”.
  • To access the %MW0 register, replace the %MW with a “4x” and change the data type to 16-Bit type…
  • To access a floating point variable (such as %MF0 or %MF2), replace the %MF with a “4x” and change the data type to 32-Bit Float….
  • To access a double word (such as %MD0 or %MD2), replace %MD with a “4x” and change the data type to 32-Bit…
  • To access a bit within a memory word, use “4x’_Bit”.

Project example for TSX-37-Micro

Download here the project