Modbus Parameter Specifications

Table Of Contents
MODBUS ACE V1.00
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DocNo.: 634505DocNo: 446144DocNo.:358982DocNo.:322523DocNo.:309753DocNo.:303997DocNo.:276241DocNo.:256078DocNo.:196392 ·Template: 2 dated 10/6/2003 ·File: ext001931381.docx ·Last printed 9/30/2019 10:29:00
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Form 1003
1.2.1 Command from master
A master device is a PC or a control unit, for example.
Start synchronization:
Start synchronization is provided by a silent interval of at least 3.5 bytes.
The next following byte is then interpreted as the first byte of a frame (i.e. address).
The interval between the individual bytes of a frame must not exceed 1.5 bytes.
Address:
The size of the address field is 8 bits.
Address values between 1 and 247 are permitted
The address 0 is intended for broadcast commands (i.e. command to all fans in the network).
Command:
The following commands of the general specification "MODBUS Application Protocol Specification V1.1" are
supported:
Code
Command
0x03
Read holding register
0x04
Read input register
0x06
Write single register
0x08
Diagnostics
0x10
Write multiple register
The other commands are not supported.
ebm-papst has additionally defined the following commands:
Code
Command
0x43
Read holding register addressed by serial no.
0x44
Read input register addressed by serial no.
0x46
Write single register addressed by serial no.
0x50
Write multiple register addressed by serial no.
Data:
The number of data bytes and their meaning differ depending on the command.