Mitsubishi PLC programming, there are two advertising light boxes, the first light box is on 10 seconds, and the second light box is on 10 seconds. The two light boxes flash alternately for 20 seconds. Try the ladder diagram below, which has been verified by simulation.

For the convenience of simulation, the two light boxes flash alternately 10 second. If you want to flash for 20 seconds, change the T0 timer setting to K400.

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