ABB A43, User Manual

Page: 103 / 295

Communication with Modbus
2CMC48001M0201
103 A43/A44
Revision: C User Manual
9.2.2 Function Code 16 (Write multiple registers)
General
Function code 16 is used to modify settings in the meter, such as date/time, to
control output and to reset values, such as power fail counter. It is possible to write
up to 123 consecutive registers in a single request. This means that several
settings can be modified and/or several reset operations can be performed in a
single request.
Request frame A request frame has the following structure:
Slave Function Start No. of Byte Register Error
Address Code Address Registers Count Values Check
Example of a
The following is an example of a request (set Date/Time to November 11, 2010,
request
12:13:14):
Slave address 0x01
Function code 0x10
Start address, high byte 0x8A
Start address, low byte 0x00
No. of registers, high byte 0x00
No. of registers, low byte 0x03
Byte count 0x06
Value of register 0x8A00, high byte 0x0A
Value of register 0x8A00, low byte 0x0B
Value of register 0x8A01, high byte 0x0B
Value of register 0x8A01, low byte 0x0C
Value of register 0x8A02, high byte 0x0D
Value of register 0x8A02, low byte 0x0E
Error check (CRC), high byte 0x8C
Error check (CRC), low byte 0x82
In this example the master sends a write request to the slave that has the
Modbus address 1. The first register to write is 0x8A00 and the number of
registers to write is 0x03. This means that the registers 0x8A00 to 0x8A02 are
written. Register 0x8A00 is set to the value 0x0A0B, and so on.