Siemens 200-SMART analog liquid level ladder diagram sharing

1. There are 5 sets of molds and 800mm high water in the water tank, then close the cover and start heating. When the water level drops to 700mm, water will be automatically added to the water tank to 800mm high and then stop.

2. Open the tank cover and take out two sets of molds. The water level will be 600mm. Then close the cover and start heating. When the water level drops to 500mm, water will be automatically added to the tank to 600mm.

Note: Each time the cover is closed, the liquid level is reset. When the mold is taken out or put in, the liquid level will definitely change. Then after closing the cover, the PLC will read the liquid level again to achieve the purpose of replenishing water to a height of 100mm in the water tank.

I am currently a beginner and need to use 200SMART's ladder diagram to write notifications.

This is the instruction I chose before, but I don’t know how to combine and apply it.

1. If the number of molds partcount = 5, the liquid level high limit = 800mm, the liquid level low limit = 700mm; if the number of molds = 3, the liquid level high limit = 600mm, the liquid level low limit = 500m.

2. If the liquid level < the liquid level low limit, start replenishing water, if the liquid level > the liquid level high limit, stop replenishing water.

The basics are to have analog processing, SCALSE, digital conversion, and the main thing is to plan the program judgment execution logic.

Every time the lid is closed, the PLC does not know how many molds are inside. Does it need manual input? A limit switch is installed on the lid to detect the opening and closing of the lid each time it is closed. Only when the number of molds is known can the corresponding water level height be known.