Programming example for real PLCs.

Includes problem statement and solutions for three automation systems:

-EasyPLC (Nirtec)

-TIA PORTAL v.15 (Siemens)

-RSLogix 5000 (Rockwell)

The objective is to weigh the parts and use RFID system to write the parts weigh (each part has a magnetic tag), then feed the parts buffer storage (convey 2). Use the Parts distribution convey to pass one by one part to the Conveyor 4. 

Operating instructions for the proposed system:

The weigh Station uses one PLC output to start to weigh, and returns one analog value (PLC analog Input) to give the weigh part value. When the Convey 1 is activated, automatically feeds parts to the system.

Use the inductive SW1 to detect the part presence in the weigh station to stop the Conveyor1 and start the weight. Once the weigh system has weighed the part returns one analog value then use the RFID system to save the value on the part tag (using one digital PLC output to activate the write command, and 8 digital PLC outputs to set the value in binary format). 

Once the part has been weighed and their value saved, start again the conveyor and feed the parts buffer storage (convey 2), use the convey 3 to distribute one by one the parts in the Convey 4 (this is because the pieces cannot be delivered continuously so that the reject station can discriminate the pieces correctly). Use inductive SW2 to detect line saturation and SW3 to manage the parts transfer to Convey 4.

When the parts arrives to the inductive Sw4, use the RFID system to read their magnetic tag in order to get their weigh, if this is less than 2 Kgr, use the Reject cylinder to reject the part (using one digital PLC Output), use the signal from inductive SW5 to activate the reject cylinder if is the case. If the part weight is greater or equal than 2 Kgr the part must continue forward

(This exercise is part of the Tutorial Manager package where you can find 20 completed and solved automation exercises)