Yaskawa VS-616G5 Modbus Plus Communication Card - Manual (Page 48)

9-4 Examples
Example #2
Read Output Frequency from Drive #3
This example will show how to read the output frequency of a VS-616G5 drive on the MB+
network.
In this example, an input to the PLC will be used to initiate the MSTR that will read the output
frequency. This input will be addressed at 10002.
The Output Frequency is held in the register with data code F005h.
In this example, the MSTR control registers will start at register 40030. The MSTR data register
will start at register 40039. There will be 1 MSTR data register. The MSTR function inserted into
the ladder logic would look like:
10002 00015 00013
00014
00013
00015
The Control Block registers must be loaded with the following data before the MSTR block is
executed:
CONTROL BLOCK
Register
Number
Register
Description
Register
Data
Data
Description
40030 Operation Code 0002h 0002h = Read from Multiple Registers
40031 Network Error Code 0000h The error code returned by Modbus Plus
communications
40032 Number of Registers 0001h Read from 1 consecutive register
40033 Register Data Code F005h Data code for output frequency command
40034 Routing 1 0003h Modbus Plus node address of drive = 0003h
40035 Routing 2 0001h End of routing path = 0001h (Modbus Plus
requirement)
40036 Routing 3 0000h This routing register is not used, must be set to 0
40037 Routing 4 0000h This routing register is not used, must be set to 0
40038 Routing 5 0000h This routing register is not used, must be set to 0
The Data Block register will be filled by the PLC with the Drive #3 Output Frequency data after the
MSTR block has been executed.
DATA BLOCK
Register
Number
Register
Description
Register
Data
Data
Description
40039 Freq. Reference READ 60.00 Hz = 6000 (decimal) = 1770h
40030
40039
MSTR
#0010