Functional detail

PID-regulator
The inverter MFC710 has a PID-regulator (proportional-integral-differential). This regulator can stabilize the parameter within a specific range of values (figure below).

Application object: constant pressure water supply equipment, coal mine tape machine, etc

PLC controller
The MFC710 has a built-in PLC controller to control the operation of the inverter or control any process. When parameter 5.144 is set to “YES”, the PLC controller is turned on.
The basic attributes of PLC control system:

1. 48 general purpose 3-input modules, each capable of performing any one of 43 logic, arithmetic, timing functions
2. Sequence generator module, can edit up to 8 state sequences – each state has an independent working time
   Both states can be changed by external signals
3. Two 8-input multiplexers can select one of the 8 input values as output according to the control signal.
4. The 5-point construction unit of the X-Y curve can be used as a reference unit for a certain feature
5. 24 programming constants that can be used as PCH (can be used as factors when calculating).
6. The execution time of PLC program is less than or equal to 10ms
   The output of each PLC module is PCH and the input is pointer, which is why it is possible to interoperate between their internal modules
   And can be connected with the parameters of the frequency converter to form the structure of the control system.

The inverter is controlled by RS connection
The inverter MFC710 offers RS232 and/or RS485(depending on the type) communication ports. It can control the operation of the device through a computer or an external controller. The basic attributes of RS communication connection are as follows:

• Transfer rates of 1200,2400,9600 or 19200 bits per second
• Byte format: 8 data bits, no parity, 2 stop bits
• Transmission protocol: MODBUS mode RTU
• The validity of the transmission is checked by CRC verification and verification
• Set the port number of the inverter by parameter (usually 12)
• Support MODBUS command: Command 3? “Read the register”? Allows reading of individual registers of the inverter or up to 127 register modules. Command 6? “Write Register” – Write to a separate register of the inverter
• Can read working modes, control start/stop, read and write reference units
• All parameters of the inverter can be read and written as if using the operation panel
  All 512 PCHS can be read and 64 of them can be written, which are specially prepared for RS connections

Function: pump unit controller
The inverter’s built-in pump (or fan) control system can control up to 5 pumps (or fans). The standard inverter MFC710 has 4 digital outputs and can control 4 pumps. The fifth pump can be connected via an optional expansion module. One of the pumps can adjust the speed (connected to the inverter), and the other pumps are automatically connected to the power supply network when needed. The operating frequency (pressure) and the number of operating pumps are adjusted by feedback from the inverter PID-regulator or directly from a reference unit. One pump operates under the MFC710 regulation of the inverter and is called the “main pump”. Other pumps turn on or off as needed and operate from the power supply network (they are called attached pumps). The frequency converter determines which pump is the main pump and can automatically replace the main pump and open and close the attached pump. If the system is disconnected from the power supply network, after re-connecting the power supply, the same pump operates as the main pump. The operating time before disconnection is recorded and added to the operating time of the main pump after restart.
If the main pump is blocked, the other pumps will be shut down immediately. The system will then start a pump as the main pump, this pump must be unblocked and can be controlled by the frequency converter. The main pump can be forcibly replaced by briefly stopping it from operating.

Correction computer
Inverter MFC710 has built-in correction calculator (RC) (figure below)

This function allows the torque of the motor to adapt to the diameter of the current drum, so it can roll with a constant force. In order to determine the current diameter of the drum, information about the line speed of the drum medium must be available. In the example shown below, the line speed signal is obtained from the frequency converter and coordinated with the production line.

Application field:
The production machinery belonging to constant torque load is relatively most, such as air compressor, Roots blower, ball mill, injection molding machine, injection plug pump, gear pump, press, plate rolling machine, extruder, wire drawing machine, drawing machine, calender, grinder, drill machine, conveyor belt, crane (translation and ascent), Elevator, carrier, blow molding machine, feeder, mixer, extrusion machine, printing machine, food processor, food packaging machine, wood processing machine, etc.