ProSoft MVI69E-MBS - Preset Multiple Registers (Function Code 16)

Reference MVI69E-MBS ♦ CompactLogix Platform
User Manual Modbus Serial Enhanced Communication Module
Page 116 of 154 ProSoft Technology, Inc.
June 28, 2017
7.2.12 Preset Multiple Registers (Function Code 16)
Query
This Function Code allows you to modify the contents of a Modbus 4x range in
the slave. This writes up to 125 registers at time. Since the controller is actively
scanning, it also can alter the content of any holding register at any time.
Note: Function codes 5, 6, 15, and 16 are the only messages that are recognized as valid for
broadcast.
The example below is a request to write 2 registers starting at register 40002 in
slave 11.
Note: This is the structure of the message being sent out to the Modbus network. The byte values
below are in hexadecimal display.
Node
Address
Func
Code
Data Start
Address
High
Data Start
Address
Low
Number
of Points
High
Number
of Points
Low
Byte
Count
Data
High
Data
Low
Data
High
Data
Low
Error
Check
Field (2
bytes)
0B
10
00
01
00
02
04
00
0A
01
02
CRC
Response
The normal response to a function 16 query is to echo the address, function
code, starting address and number of registers to be loaded.
Node
Address
Func
Code
Data Start
Address
High
Data Start
Address
Low
Number
of Points
High
Number
of Points
Low
Error Check
Field (2 bytes)
0B
10
00
01
00
02
CRC