ICTS-Panel Box Wiring

Yesterday after spending sometime reading the CPM1A I realize the I/O wiring mistake with the PLC. First I thought all the inputs switches must be tie to common. Instead I found out that whatever connected to input common must pass through a DC 24V supply before connecting to the inputs. The good thing the power supply orientation is optional. The common input can be connected to positive or negative of DC power supply as long as all the input are passed through the same supply.

As for the output, it also the same thing. I chose COM3 because it has 4 ports tied to it, output 4, output 5, output 6, and output 7. I connect output 4 to pneumatic valve, output 5 to conveyor D, output 6 to conveyor C, and output 7 to conveyor B. Since both input and output were connected already, then due to this wiring problem, I have to rework it today.

Due to unavailability of right switches for START STOP and EMERGENCY, I decided to use one simple toggle switch to replace the EMERGENCY. As for START STOP I will take it out from the Programmable Logic Controller (PLC) program. The new switch I call it RUN/STANDBY. This one switch will do both of those two switches job. The logic behind this change is, once the panel box is ON, all of the I/O basically are ready to operate. By having EMERGENCY and START STOP it just a matter of stopping the conveyors and pneumatic valve from operating only.

By installing RUN/STANDBY, it is set to RUN when machines are ready to be run and STANDBY while feeling up the conveyor with the moon cakes. During standby, the valve will be shut off meaning the packaging machine and auto feeder sachet machines can run as usual. Once all 3 conveyors (BCD) are full, then if the operator switch the control box to RUN, the valve will turn ON if there is a cutter signal received by PLC.

As to replace EMERGENCY switch, just turn OFF the panel box power supply to switch off all, or switch off the individual AC source at respective conveyors, or turn the switch box to STANDBY mode. One thing for sure, any of these action surely will stop the supply of moon cake to packaging conveyor. This is the revise ladder diagram.