Vacon 100 - 6 Communications; Data Addresses in Modbus Messages; Modbus Memory Map

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6. COMMUNICATIONS
Features of the Modbus-Vacon interface:
• Direct control of Vacon drive (e.g. Run, Stop, Direction, Speed reference, Fault reset)
• Full access to all Vacon parameters
• Monitor Vacon status (e.g. Output frequency, Output current, Fault code)
6.1 Data addresses in Modbus messages
All data addresses in Modbus messages are referenced to zero. The first occurrence of a data
item is addressed as item number zero. For example:
• The coil known as ‘Coil 1’ in a programmable controller is addressed as ‘Coil 0000’ in
the data address field of a Modbus message.
• Coil 127 decimal is addressed as ‘Coil 007E hex’ (126 decimal).
• Holding register 40001 is addressed as register 0000 in the data address field of the
message. The function code field already specifies a ‘holding register’operation. There-
fore the ‘4XXXX’ reference is implicit.
• Holding register 40108 is addressed as register 006B hex (107 decimal).
6.2 Modbus memory map
The Vacon variables and fault codes as well as the parameters can be read and written from
Modbus. The parameter addresses are determined in the application. Every parameter and ac-
tual value have been given an ID number in the application. The ID numbering of the parameter
as well as the parameter ranges and steps can be found in the application manual in question.
The parameter value shall be given without decimals. If several parameters/actual values are
read with one message, the addresses of the parameters/actual values must be consecutive.
Table 12. Supported functions
Function
code
Current terminology Access type
Address
range (hex)
TCP/RTU
1 (0x01) Read coils Discrete 00000-0FFFF TCP
2 (0x02) Read Input Discrete Discrete 10000-1FFFF TCP
3 (0x03) Read holding registers 16bit 40000-4FFFF TCP&RTU
4 (0x04) Read input registers 16bit 30000-3FFFF TCP&RTU
5 (0x05) Force single coils Discrete 00000-0FFFF TCP
6 (0x06) Write single register 16bit 40000-4FFFF TCP&RTU
15 (0x0F) Force multiple coils Discrete 00001-0FFFF TCP
16 (0x10) Write multiple registers 16bit 40000-4FFFF TCP&RTU
23 (0x17) Read/Write multiple registers 16bit 40000-4FFFF TCP&RTU
NOTE: Broadcasting not supported in TCP.
Broadcast supported with function code 06 and 16 in RTU