Step 1.2.2. Enter Required Configuration Data

For each device port in the project, a separate alternate configuration file must be created. The alternate configuration file must be located in the data sub-directory for each project.

For each alternate configuration file, the file name is based on the port configuration.


File name for the first port.

This file contains any devices configured on the first port that use the alternative configuration.


File name for the second port.

This file contains the alternate configuration information for devices.

The same convention is followed for devices configured for use on the other Modbus Ethernet ports.

In the alternate configuration file, for each device using this scheme, the following information is required:

  1. CIMPLICITY device name

  2. Number of bytes used for each of the following memory references:

Coils (COILS)

Discrete Inputs (DISC INPUTS)

Input Registers (INPUT REG)

Holding Registers (HOLDING REG)

General Reference File 1 (GEN REF FILE1)

General Reference File 2 (GEN REF FILE2

General Reference File 3 (GEN REF FILE3

General Reference File 4 (GEN REF FILE4

General Reference File 5 (GEN REF FILE5)

General Reference File 6 (GEN REF FILE6)

General Reference File 7 (GEN REF FILE7)

General Reference File 8 (GEN REF FILE8)

General Reference File 9 (GEN REF FILE9)

General Reference File 10 (GEN REF FILE10)

Double Precision Input Registers (DP_INPUT REG)

Double Precision Holding Registers (DP_HOLDING REG)

For example, if there are 16384 coils on the device, the coil byte count in the configuration file would be 2048 (8 coils per byte). Similarly, if there are 32767 holding registers on the device, the byte count of holding registers in the configuration file would be 65534 (2 bytes per holding register).

More information

Sample Alternate Configuration File.

Option 1.2. Set up  Advanced Modbus TCP/IP Configurations.