Siemens UL 1066, Operating Instructions Manual

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MODBUS Functionality
Transmission Protocol
The COM16 module operates in the RTU transmission mode. ASCII transmission mode is not supported.
Overview of supported Functions
The COM16 module provides the following MODBUS function codes for accessing the data contained in the WL circuit breaker.
FC Name Description
02: Read Discrete Inputs Reads the state of the Bits in the Status Register
01: Read Coils Reads the state of multiple Control Bits and Extra Flags
05: Write Single Coil Sets the state of a single Control Bit or Extra Flag
15: Write Multiple Coils Sets the state of multiple Control Bits and Extra Flags
04: Read Input Registers Reads the Basic Data Registers. Three Basic Types (1, 2 and 3) are supported.
03: Read Holding Registers Reads a complete data set.
16: Write Multiple Registers Writes a complete data set.
07: Read Exception Status Reads the state of eight Exception Status bits
08: Diagnostics
Function provides a method for checking the communication between the master
and the slave
11: Get Comm Event Counter Returns a status word and an event count from the communications event counter
12: Get Comm Event Log Returns a status word, event count, message count, and a field of event bytes