The Modbus TCP/IP device communication enabler is designed to operate with devices compatible with the Open Modbus/TCP specification release 1.0. Because the Modbus TCP/IP protocol is supported by a number of vendors on a variety of different devices and because the layout of memory varies from device to device, the range of the various defined memory types varies.
As part of its initialization, the device communication enabler determines the size of the various memory types. By default, the size of the memory is determined by probing the device to determine the range of memory.
This method may not be appropriate for all devices. For devices that have any of the following characteristics, the alternate configuration file described below should be used:
Devices with non-consecutive memory. (All configured device points must be correctly configured to maintain reliable communication.)
Devices that do not support the protocol for reading multiple quantities of consecutive memory locations for all of the following (independent of point configuration):
General Reference Registers
Double Precision Input Registers
Double Precision Holding Registers
Environments that are either noisy or busy such that a retry count greater than 5 is required in order to reliably maintain communication with the device.
Enter model information.
Enter required configuration data.
Step 1. Install the Modbus TCP/IP Option.