What is the setup procedure to establish the communication of Altivar 21 Drive via ModBus RTU or ModBus Network.


30 September 2021

The procedure for communication setup of the Altivar 21 Drive via ModBus RTU or ModBus Network is as follows:

1. Pass the register address of Altivar 21 Drive to the PLC (ModBus Master). This enables the PLC to read/write all the parameters to control. Refer the attached Manual to know about the register addresses.
2. To control the drive with ModBus, configure the command channel (CMOD = 2) and the reference channel (FMOD = 4).
3. To configure the ModBus parameters (baud rate, address ...) go to menu F8**. This part is described in the programming manual. Control word address is Hex FA00h and Frequency reference address is Hex FA01h.
Refer attached Altivar 21 ModBus User Manual for learning about the Altivar 21 Control, address for feedback & frequency reference including pin out of RJ 45 ModBus Port.