Modbus Communication
‑33‑
After the read and write settings, click ""OOKK"" to return to the programming
interface.
Instances
1. Write the frequency (F0‑03 is set to 9).
Data conversion: Multiply the desired frequency value a by 100, convert it to an
integer, and then write it into 1000H.
The following figure shows the configuration and the program.
2. Implement start/stop control on the AC drive (F0‑02 is set to 2).
Assign a value to the D component corresponding to the station address 2000H to
control forward running, reverse running, and stop of the AC drive through
communication. 2000H is defined as follows: 1
1: Run in forward direction; 2: Run in reverse direction; 3: Jog in forward direction;
4: Jog in reverse direction; 5: Coast to stop; 6: Decelerate to stop; 7: Reset upon
fault
The following figure shows the configuration and the program.
The PLC soft component address corresponding to 2000H is D2. Therefore, to
control the AC drive to run in forward direction through communication, write 1 to
D2. Similarly, to control the AC drive to decelerate to stop, set D2 to 6.
3. Read the bus voltage.
Convert the bus voltage address U002 to 7002 based on the conversion rule
(convert U in the high‑order 2 bits to 7, and convert the low‑order 2 bits to a
hexadecimal equivalent). The actual bus voltage is the read bus voltage a divided
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