VACON CX
Modbus user’s manual
Page
13
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Vacon Oy
Phone +358-201-2121
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7.
MODBUS-VACON CX INTERFACE
Features of Modbus-Vacon CX interface:
•
Direct control of Vacon CX ( e.g. Run, Stop, Direction, Speed reference, Fault reset)
•
Full access to all Vacon CX parameters
•
Monitor Vacon CX status (e.g. Output frequency, Output current, Fault code ..)
•
Diagnostic of modbus communications
7.1
Modbus function codes
7.1.1
Function code 1, Read Control Bits
This function is used to read control bits.
The transaction frames:
Query:
Slave
address
Function
code
Starting
Address HI
Starting
Address LO
Number of
points HI
Number of
points LO
CRC16
1 byte
1 byte
1 byte
1 byte
1 byte
1 byte
2 bytes
Response:
Slave
address
Function
code
Byte count
Data bits
CRC16
1 byte
1 byte
1 byte
1 byte
2 bytes
7.1.2
Function code 2, Read Status Bits
This function is used to read status bits.
The transaction frames:
Query:
Slave
address
Function
code
Starting
Address HI
Starting
Address LO
Number of
points HI
Number of
points LO
CRC16
1 byte
1 byte
1 byte
1 byte
1 byte
1 byte
2 bytes
Response:
Slave
address
Function
code
Byte count
Data bits
CRC16
1 byte
1 byte
1 byte
1 byte
2 bytes
7.1.3
Function code 3, Read Parameters
This function is used to read VACON CX parameters.
The transaction frames:
Query:
Slave
address
Function
code
Starting
Address HI
Starting
Address LO
Number of
points HI
Number of
points LO
CRC16
1 byte
1 byte
1 byte
1 byte
1 byte
1 byte
2 bytes
Response:
Slave
address
Function
code
Byte count
Data HI
Data LO
CRC16
1 byte
1 byte
1 byte
1 byte
1 byte
2 bytes