Yaskawa VS-616G5 Profibus-DP Control Card SI-P - Manual (Page 13)

VS-616G5 Option Instruction Manual: Profibus-DP Control Card SI-P Page 13
MODBUS Message Area
This area is used to transfer MODBUS messages to the inverter. The Profibus-DP master places the
MODBUS command in the output area. The response generated by the inverter is placed in the input area.
The messages can contain 1 - 4 words of data. Since this procedure may take several Profibus
communication cycles, a handshaking protocol is required. The protocol indicates when new commands
and responses are available in the input and output area. Please refer to Yaskawa technical document
PI#95029 entitled “MODBUS Communication for the VS-616G5 inverter” for details and parameter
register addresses.
MODBUS command message structure
The MODBUS command message is built up as shown in Table 10.
Table 10: MODBUS Command Message Structure (PDP Master ⇒ G5 SI-P)
Byte Name Function
16 MODBUS Function Code MODBUS command code.
03H: Read command
10H: Write
command
Other: Not supported
17 MODBUS Starting address HI Inverter start address reference, HI byte
18 MODBUS Starting address LOW Inverter start address reference, LOW byte
19 MODBUS Data Length Write: No of valid bytes in the data area
Read: No. of requested bytes for read operation.
20 MODBUS Data 1 HI byte for Data word 1. Write operation
21 MODBUS Data 1 LOW byte for Data word 1. Write operation
22 MODBUS Data 2 HI byte for Data word 2. Write operation
23 MODBUS Data 2 LOW byte for Data word 2. Write operation
24 MODBUS Data 3 HI byte for Data word 3. Write operation
25 MODBUS Data 3 LOW byte for Data word 3. Write operation
26 MODBUS Data 4 HI byte for Data word 4. Write operation
27 MODBUS Data 4 LOW byte for Data word 4. Write operation
28 Not used Reserved for future use
29 Not used Reserved for future use
30 Not used Reserved for future use
31 Handshake register See Handshaking Register section