Lenze ESVZAR0 RS-485 - Manual (Page 14)

12 CMVMB401C
Modbus Protocol
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 Supported Function Codes
The Modbus 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).
• In some instances, multiple words can be read for a single register. When this is done for the registers below,
the response from the drive will be for the number of words, rather than the number of registers, requested:
• Register #500 (Fault History) can be read as 1 word (returning the two most recent faults) or as 4 words (returning
the entire fault history).
• Register #511 (Total kWh) can be read as 1 word (returning only the low word of the 32-bit register value) or
as 2 words (returning the complete 32-bit register value).
• Register #540 (Total Runtime Hours) can be read as 1 word (returning only the low word of the 32-bit register
value) or as 2 words (returning the complete 32-bit register value).
• Register #541 (Total Power On Hours) can be read as 1 word (returning only the low word of the 32-bit register
value) or as 2 words (returning the complete 32-bit register value).
06 - Preset Single Register (4X references)
Write a single register.
16 - Preset Multiple Registers (4X references)
While code 16 is supported it’s implementation is limited to addressing only one register per write.