In the process of application programming, it is necessary to correctly select the parameters which can reflect the production process as the control parameters, and correctly deal with the mutual restriction and cooperation among the executive appliances and programming elements, that is, the interlocking relationship. T37 delay 3 s as the starting condition of q0.0, T38 delay of 5 s as the turn off condition of q0.0.Įxperience design method and matters needing attention The circuit requires that the output signal is on only after the input signal is stopped for a period of time while the output signal is off after the input signal is 0ff. I0.0 is the start button and i0.1 is the stop button.ģ. Delay stop to control the delay stop when the time is up.
When the time is up, the normally open contact acts to make q0.0 act.Ģ. I0.4 is emergency stop buttonĭelay start control design delay start program, the use of the intermediate relay (internal memory m) self-locking state to enable the timer to continuously time. If you want to stop q0.0, you must stop q0.1 first. Q0.1 can be stopped only after q0.2 is stopped.
The one-way sequential stop control circuit is to stop the executed mechanisms in a certain order. Q0.1 can be started only after q0.0 is started, and q0.2 can be started only after q0.1 is started.Ģ. The unidirectional sequential start control circuit is based on the pre-determined sequence of production process, under the action of various input signals, each actuator in the production process automatically and orderly acts. One way sequential start stop control circuit There are many programming methods, and setting and reset instructions are available Multi output self-locking control means multiple load self-locking output. The main characteristic of the circuit is that it has the function of “memory”.Ģ multi output self-locking control circuit (set, reset) Each class starts from the left bus, passes through the contacts and coils, and ends at the right bus.ġ single output self-locking control circuitīoth start signal i0.0 and stop signal i0.1 stay on for a short time. The ladder diagram consists of several classes, arranged from top to bottom. In the PLC program diagram, the left and right buses are similar to the control power lines of relays and contactors, the output coils are similar to loads, and the input contacts are similar to buttons. It is easily accepted by electrical technicians and is the most widely used PLC programming language. It has the characteristics of image, intuition and practicality. Ladder diagram is derived from simplifying symbols on the basis of commonly used relay and contactor logic control.
Ladder diagram language follows the form of relay control circuit. LAD (ladder logic programming language) is the most used graphic programming language of PLC, which is called the first programming language of PLC.