I. AC10 Inverter
The Parker AC10 inverter meets the requirements for speed and torque control of motors with low cost, simple installation, and reliable operation. It features SENSORLESS VECTOR CONTROL, CLOSED LOOP CONTROL, and V/Hz control modes. It integrates an RS 485 communication port and can control both 3-phase asynchronous and 3-phase synchronous PMAC motors.
The AC10 inverter integrates built-in MACRO functions for applications such as PID CONTROL, PRESET SPEED CONTROL, RAISE/LOWER, and supports logical and value calculations like a PLC. Parameters can be set via the keypad or the DSELite programming software.
II. Siemens S7-1200 PLC
The Siemens S7-1200 PLC is one of the most popular PLC models today due to its compact design and affordable cost. The S7-1200 PLC can be expanded with additional signal modules and external modules to extend CPU functionality.
For this reason, Kỹ Thuật Việt has created this article to guide the communication between the S7-1200 PLC and the AC10 inverter.
III. Advantages of Using Modbus RTU RS485 Communication between PLC S7-1200 and Parker AC10 Inverter
There are two methods to control the inverter using a PLC:
- Control the inverter using hardware I/O connections.
- Control the inverter via Modbus RS485 communication.
♦ Using hardware I/O connections for inverter control requires many Digital or Analog signals. In industrial machines where the PLC must control multiple devices, additional Digital and Analog expansion modules are needed, increasing costs and requiring more installation space.
♦ Advantages of using PLC S7-1200 to control the inverter via Modbus RS485 communication:
- High flexibility: Modbus communication enables communication between multiple devices using just two RS485 signals. The Modbus protocol supports PLC connections with up to 247 slave devices. Additionally, the PLC can read data from the inverter, such as stored error logs and operational parameters, which is not possible with direct wiring.
- Reduced setup and control errors: Modbus communication enables fast and efficient data exchange between devices, minimizing errors and improving control accuracy.
- Increased system speed and efficiency: Using Modbus communication between the PLC and inverter ensures quick and precise data exchange, enhancing automation system speed and performance.
- Cost savings and improved system availability: Modbus is an open protocol, reducing system deployment costs and enhancing system availability.
- Easy maintenance and upgrades: Since Modbus communication follows a standard protocol, maintaining and upgrading the automation system is more convenient.
Using Modbus communication between the PLC and inverter improves flexibility, accuracy, speed, and system performance while reducing costs, increasing availability, and simplifying maintenance and upgrades.
IV. Required Equipment
► AC10P Inverter
► S7-1200 CPU and one RS485 communication module CM1241
► Communication cable
V. Communication between PLC S7-1200 and AC10 Inverter
To establish communication between the PLC and inverter, two steps are required:
- Configure the AC10 Inverter
- Program the S7-1200 PLC
V.1. AC10 Inverter Configuration
Communication parameters need to be configured for the inverter.
| Function Code | Function Definition | Setting Range | Default Value |
|---|---|---|---|
| F200 | Source of start command | 0: Keypad command 1: Terminal command 2: Keypad + Terminal 3: MODBUS 4: Keypad + Terminal + MODBUS |
4 |
| F201 | Source of stop command | 0: Keypad command 1: Terminal command 2: Keypad + Terminal 3: MODBUS 4: Keypad + Terminal + MODBUS |
4 |
| F203 | Main frequency source X | 0: Digital setting memory 1: External analog AI1 2: External analog AI2 3: Reserved 4: Stage speed control 5: No memory by digital setting 6: Reserved 7: Reserved 8: Reserved 9: PID adjusting 10: MODBUS |
0 |
| F900 | Inverter Address | 1 – 255 | 1 |
| F901 | Modbus Mode Selection | 1: ASCII mode 2: RTU mode |
2 |
| F903 | Parity Check | 0: Invalid 1: Odd 2: Even |
0 |
| F904 | Baud Rate (bps) | 0: 1200 1: 2400 2: 4800 3: 9600 4: 19200 5: 38400 6: 57600 |
3 |
V.2. Siemens S7-1200 PLC Programming
Using TIA Portal software to program the S7-1200 PLC.
V.2.1. PLC Hardware Configuration
V.2.2. Writing the Program
Using the MB_COMM_LOAD block to set up communication.
• REQ: The signal input for scanning the block. Choose FirstScan to be declared only once when running.
• PORT: Communication address. Selecting local will automatically display address 272.
• BAUD: Baud rate. Choose the same as the inverter (9600).
• PARITY: Choose parity check. Select the same as the inverter, which is 0.
Use the MB_MASTER block to write or read data for the inverter.
• MB_ADDR: The address of the inverter that needs to receive the command.
• MODE: 1 is for transmitting data to the inverter, 0 is for reading data back to PLC at DATA_PIR.
• DATA_ADDR: The parameter address.
V.2.3. How to Convert DATA_ADDR
Example: We want to issue a run command for the inverter.
Parameter address 2000 in HEX converts to DEC as 8192, then adds 40001 according to the Modbus standard. So the final converted parameter is 48193.
Speed Transmission
If a run command is given to the inverter but no speed is set, the motor will not operate.
For AC10 inverters, parameter address F113 is the target frequency for motor speed control.
At DATA_ADDR, parameter F113 will be converted as follows:
• 113: The first “1” is the high-order byte in hexadecimal, kept as is.
• 113: The last “13” is the low-order byte, converted to hexadecimal as “D”.
Thus, F113 in hexadecimal is 10D. When converted to decimal, it becomes 269. Adding 40001 results in 40270.
At DATA_PIR: Write the running frequency into the inverter’s address. For example, 2000 corresponds to 20.00Hz.
Currently, Kỹ Thuật Việt is the sole authorized distributor of Parker Hannifin in Vietnam, offering the AC10 inverter series with power ranges from 0.75 to 400 kW, available in 1-phase 220V and 3-phase 380V models.
