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Modular Gateway

When was the Modbus TCP gateway module discontinued?

The product was discontinued in December 2022. Enclosed is the corresponding document.

The assignment of data exchange is mysterious. Is there an example available?

Up to 512 bytes are transferred in the little Endian format between two gateway modules. Output data and input data are shared between the gateway components.

Modbus TCP

PROFIBUS

Modbus TCP

PROFIBUS

FC 0x03 Read Holding Register 1–122

Output offset 0–244 bytes

FC 0x10 Write Multiple Registers 1025–1147

Input offset 0–244 bytes

  • Have in mind that Modbus registers per definition use 16 bits or two bytes.

  • PROFIBUS can use 244 bytes for input/output in each direction.

  • Therefore, just 122 registers are useable for the access of the 244 bytes.

Can I use RS232 to Ethernet/IP?

Yes, you can do it with the following components:

Do I need 3 gateways each on PROFINET to integrate 3 Modbus-TCP participants into the system, or is one gateway sufficient?

  • All modular gateway modules act as slaves.

  • Therefore, three Modbus TCP masters would then access one slave together.

  • From a purely technical point of view, common access is possible considering that the process data 512 bytes each for input and output direction are sufficient.

  • Furthermore, it has to be considered that the Modbus TCP masters then also write into different registers.