Technical data

Chapter 4 – Communication
4-4 RS485 and RS232 Adapter Installation and Start-up Guide
Function Codes
The ACS 160 supports the Modbus function codes given in Table 4-3. If any
other function codes are used ACS 160 returns an exception response with
error code 01 (illegal function).
Table 4-3 Function codes.
The Control Word and the Status Word
Holding registers: 40001 (Control Word), 40004 (Status Word)
The Control Word (CW) is the principal means for controlling the drive from a
fieldbus system. It is effective when the drive is in external (remote) control and
the controlling commands are received through serial communication channel
(set by parameters 1001 EXT1 COMMANDS, 1002 EXT2 COMMANDS and
1102 EXT1/EXT2 SEL).
The Control Word (detailed in Table 4-4) is sent by the fieldbus master station
to the drive. The drive switches between its states according to the bit-coded
instructions of the Control Word. See also state machine in Figure 4-1.
The Status Word (SW) is a word containing status information, sent by the drive
to the master station. The composition of the Status Word is explained in Table
4-6.
Note! Operation of Control Word and Status Word conforms to ABB Drives
Profile with the exception of Control Word bit #10 (REMOTE_CMD), which is
not used by the ACS 160.
Code Description
03 Read holding registers
06 Preset single register
16 (10 Hex) Preset multiple registers