External Signal Exchange
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Operating Manual dryve D1, ST-, DC-, EC/BLDC-Motor Control System - V2.4
6.5.4 Byte Assignment Modbus TCP Gateway Telegram
Byte
Endianness
Field
Value
Description
Byte 0
Big Endian
Transaction
Identifier
0
Identification of Modbus telegram (allocation of a response
to a command telegram). The master will set a value, e.g.
1, in the command telegram. The dryve D1 will adopt the
value 1 to the response telegram and will send it back to
the master. If the Transaction Identifier value is the same in
the command and the response telegram, both telegrams
are interrelated. If this function is not used, a 0 should be
set.
Byte 1
0
Byte 2
Protocol
Identifier
0
0 = Modbus Protocol
Byte 3
0
0 = Modbus Protocol
Byte 4
Length
0
Byte not used but must be send.
Byte 5
13 - 17
Information of how many bytes will be send in a telegram
after byte number 5. The value is 13 (0Dh) if a read
telegram is sent by the master. A 1-byte long SDO write
telegram does have the value 14 (0Eh). A 4-byte long
telegram has the value 17 (11h).
Byte 6
Unit
Identifier
0
Byte not used but must be send.
Byte 7
Function
code
43 (2Bh)
Modbus TCP Gateway (CANopen) = 43 (2Bh)
Error information output (p.85)
Byte 8
MEI type
13 (0Dh)
Modbus TCP Gateway (CANopen) = 13 (0Dh)
Error information output (p.85)
Byte 9
Protocol
option fields
/ Protocol
control
0 = read
1 = write
The value is a 0 for a read and a 1 for a write telegram.
Byte 10
Protocol
option fields
/ Reserve
0
Byte not used but must be send.
Byte 11
Node ID
0
Byte not used but must be send.
Byte 12
Object Index
SDO Object
Controlword SDO Object e.g. 60h
Byte 13
SDO Object
Controlword SDO Object e.g. 40h
Byte 14
Sub Index
SDO Object /
Sub Index
Objects Sub Index
Byte 15
Starting
Address
0
Byte not used but must be send.
Byte 16
0
Byte not used but must be send.
Byte 17
SDO Object
0
Byte not used but must be send.
Byte 18
Byte count
1-4
Byte count detail depending on the SDO Object in Byte 12
and 13. For example the Controlword 6040h is 2 Byte long
the value must be 2
Byte 19
Little Endian
Data Field
Data read/write
Information byte section. If the master sends a read
telegram to the dryve D1, it will respond with the requested
information. The information will be transmitted in byte 19 to
22, depending on the SDO Object length. If only 1-byte
shall be read the response telegram contains byte 19 only.
If the information is 4-byte long, byte 19 to 22 will be send.
A write telegram must have the length of byte 19 to 22. 1-
byte information will be set in byte 19, 2-byte information in
byte 19 to 20 and so on.
Byte 20
Data read/write
Byte 21
Data read/write
Byte 22
Data read/write
