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Siemens Simatic 505 and Modbus TCP/IP
By Martin Berutti
Product: IOD-4101 - Modbus TCP/IP Master Driver (General Modbus TCP/IP Communications)

This purpose of this technical note is to discuss Industrial Ethernet integration options for Siemens S5 PLCs with DeltaV.

Control Technology, Inc., makes an Ethernet Interface Module for the Simatic 505 controllers. The CTI 2572-A card allows effective Modbus TCP/IP communications with Modbus master devices like the DeltaV Virtual IO Module Network Gateway. Geoff Nash, Senior Software Developer at MYNAH, reviewed the CTI 2572-A manual and had the following comments:

The ModbusTCP server opens in this system starts automatically. Reads and writes use the standard ModbusTCP functions; read (coil, input, holding or input register), write (coil or register). The Modbus VIM should have no trouble accessing the registers. All register access are as 16-bit reads (either 16-bit registers or groups of 16 coils or inputs). 100 register (signed or unsigned) datasets can be used to read blocks of information. For coils and inputs, a maximum of 1600 bits can be read at a time (using a unsigned 16-bit dataset) or 96 bits using a discrete dataset.

Ordering Information

The DeltaV Virtual I/O Module (VIM) provides a native DeltaV I/O interface to open plant Ethernet networks and devices that use ModbusTCP (RTU TCP, RTU via TCP and RTU via UDP) protocol.

IOD-4101 ModbusTCP Driver for DeltaV Virtual I/O Module