9
ENGLISH
Commissioning
5
Modbus Protocol Details
5.1
Data Transmission
This drive uses the RTU (Remote Terminal Unit) transmission mode of the Modbus
Protocol and operates as a Slave device on the network. All devices communicating with
the drive(s) must be a Modbus Master.
5.2
Register Numbering
Modbus 3X and 4X register numbers are always
one greater
than the actual drive
register numbers. For example: drive register #24 would correspond to Modbus 3X / 4X
register #25.
All the register numbers referred to in this document are
drive
register numbers.
5.3
Modbus Function Codes Supported
Function codes supported by the drive are:
The function codes supported by the drive are:
03 - Read Holding Register (4X references)
04 - Read Input Register (3X references)
Note
We do not differentiate between 4X and 3X references. Therefore, function codes 03
and 04 are treated identically
.
Typically only one register (or one word of data) can be read at a time.
Exceptions to this rule are:
• Register #24 (Command Frequency) can be read as a single register or as a group
of 6 drive status registers (#24-29).
• Register #32 (low word of Total kWh) can be read as a single register or as a group
of 2 registers (#32-33).
• Register #60 (low word of Total Runtime Hours) can be read as a single register or
as a group of 2 registers (#60-61).
• Register #64 (low word of Total Power On Hours) can be read as a single register or
as a group of 2 registers (#64-65).
