This is a project that I took on at my place of employment. This project involved pulling out a PLC2/16 putting in a PLC5/30 to ease troubleshooting. Anyone who has used a Allen Bradley Terminal knows that it is not that user friendly. Changing from a PLC2 to a PLC5 required no wiring changes. They both use the same chassis and IO cards. To Convert this program required manually typing the program in. Changing the Timer addressing and the Bits. PLC2 programs use the unused outputs as bits. In this case mirrors of the Input cards in the output image table. They are addressed with O:*/* being that they are in the output table, this there for makes them very hard to identify at a quick glance. This makes troubleshooting that much harder, since telling real world from internal requires a lot of thought. When the program was complete, I used the replace command to change all internal O's to B's. Timers were addressed with O:*/*, so they all had to be converted to T:*/* also. This was a fun project.
