2-3
IM 34M06P15-03E 2nd Edition: Jan. 31, 2012-00
2.4 Function Codes
This section describes the Modbus function codes.
Support Function Codes
The functions codes supported by this module are as shown below.
Table 2.4.1 Function Code List
Function
Code
Name Description Supported
01 ($01) Read Coils Consecutively reads the status of a max. of
2,000 coils.
Yes
02 ($02) Read Discrete Inputs Consecutively reads the status of a max. of
2,000 inputs.
Yes
03 ($03) Read Holding Registers Consecutively reads the status of a max. of 125
holding registers.
Yes
04 ($04) Read Input Registers Consecutively reads the status of a max. of 125
input registers.
Yes
05 ($05) Write Single Coil Writes a single coil. Yes
06 ($06) Write Single Register Writes a single register. Yes
15 ($0F) Write Multiple Coils Consecutively writes the status of a max. of
1,968 coils.
Yes
16 ($10) Write Multiple Registers Consecutively writes the status of a max. of 123
registers.
Yes
20 ($14) Read File Record Reads a max. of 124 file records. Yes
21 ($15) Write File Record Writes a max. of 122 file records. Yes
22 ($16) Mask Write Register Mask a single register with AND or OR. Yes
23 ($17) Read/Write Multiple Registers Reads and writes multiple registers. Yes
24 ($18) Read FIFO Queue Reads FIFO tables. Yes