Yaskawa VS-616G5 Modbus Plus Communication Card - Manual (Page 47)

Examples 9-3
Example #1
Write RUN/STOP and Frequency Reference to a Drive
This example will show how to write a RUN FORWARD command and a 60.00 Hz frequency
reference to a drive. This example assumes that the drive is located at node 3.
In this example, an input to the PLC will be used to initiate the MSTR that will write the ‘Operation
Command’ and ‘Frequency Reference’. This input will be addressed at 10001.
Since the ‘Operation Command’ register (001h) and the ‘Frequency Reference’ register (002h)
are consecutive registers, one MSTR function can be used to write to both registers.
In this example, the MSTR control registers will start at register 40010. The MSTR data registers
will start at register 40020. There will be 2 MSTR data registers. The MSTR function inserted into
the ladder logic would look like:
10001 00012 00010
00011
00010
00012
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
40010 Operation Code 0001h 0001h = Write to Multiple Registers
40011 Network Error Code 0000h The error code returned by Modbus Plus
communications
40012 Number of
Registers 0002h Write to 2 consecutive registers
40013 Register Data Code 0001h Data code for run/stop command
40014 Routing 1 0003h Modbus Plus node address of drive = 0003h
40015 Routing 2 0001h End of routing path = 0001h (Modbus Plus
requirement)
40016 Routing 3 0000h This routing register is not used, must be set to 0
40017 Routing 4 0000h This routing register is not used, must be set to 0
40018 Routing 5 0000h This routing register is not used, must be set to 0
The Data Block registers must be loaded with the appropriate RUN/STOP and Frequency
Reference data before the MSTR block is executed.
DATA BLOCK
Register
Number
Register
Description
Register
Data
Data
Description
40020 Operation Signals 0001h Run Forward = bit 0/on = 0001h
40021 Freq. Reference 1770h 60.00 Hz = 6000 (decimal) = 1770h
40010
40020
MSTR
#0010