Mitsubishi PLC control inverter method

First, Mitsubishi plc analog signal control frequency converter

Hardware: fx1n type, fx2n type plc host, equipped with a simple FX1N-1DA-BD extended analog output board; Or analog input/output mixed module fx0n-3a; Or two way output fx2n-2da; Or four way output fx2n-4da module, etc.

Advantages: plc programming simple and convenient, smooth and continuous speed curve, stable work.

Disadvantages: in large-scale production lines, the control cable is very long, especially when da module uses voltage signal output, the line has a large voltage drop, which affects the stability and reliability of the system. Other, from the economic point of view, such as the control of 8 frequency converter, the need for 2 pieces of Mitsubishi plc-fx2n-4da module, its cost is the choice of extended memory communication control 5-7 times.

Two, Mitsubishi plc switching signal control Mitsubishi inverter

The output point and com point of Mitsubishi plc(mr Type or mt type) are directly connected with stf(positive forward start), rh(high speed), rm(medium speed), rl(low speed), sg and other ports of the input terminal of the inverter. Mitsubishi plc can control the initiation, suspension and reset of frequency converter through the program; It can also control the different combinations of high speed, medium speed and low speed terminals of the frequency converter to complete the multi-section speed operation.

However, because it is the selection of switching quantity to implement control, the speed curve is not a continuous smooth curve, also can not finish the fine speed conditioning. The speed control accuracy of this switching control method is not comparable with that of communication control with extended memory.

Three, plc adopts rs-485 modbus-rtu communication method to control the frequency converter

The new Mitsubishi f700 series inverter uses the rs-485 terminal to communicate with the plc using the modbus-rtu protocol.

Advantages: plc programming of modbus communication method is simpler and more convenient than rs-485 protocol-free method.

Disadvantages: the workload of plc programming is still the largest.

Four, Mitsubishi plc uses fieldbus method to control the frequency converter

Mitsubishi inverter can be built in various types of communication options, such as fr-a5nc option for cc-link fieldbus; fr-a***p(a) option for profibus dp fieldbus; fr-a5nd options for devicenet fieldbus and so on.

fx series Mitsubishi plc has the corresponding communication interface module to connect with it.

Advantages: fast speed, long distance, high efficiency, stable work, simple programming, can be connected to the number of frequency converter.

Disadvantages: high cost, much higher than the cost of the extended memory communication control.

Five, plc adopts rs-485 non-protocol communication method to control Mitsubishi frequency converter

This is a widely used method, plc use rs serial communication instruction programming.

Advantages: simple hardware, low cost, can control 32 frequency converter. Several methods of Mitsubishi PLC control frequency converter.