PLC and Automation

Certain inputs such as OK bits will agree with the count at each target. For instance, if each pulse from the encoder represents 1 mm of travel, and the target count is 20000 ? 2 (for an acceptable deviation), then the crane motion will slow down at some earlier count (typically 19800).

It will then creep to the target count and stop. If the binary OK bit agrees it is on target, the next operating cycle can proceed.

Modern PLC’s are incredibly sophisticated. They can be programmed in the traditional ladder logic. Our preference is to set the program in Functional Block form.

Each cycle of operation is clearly identified as an individual block. This has the assigned inputs and counts, and the outputs to enable and operate the specific cycle.

Each cycle progresses until the machine is back at the start point. It then waits for the next autostart input, and the automatic cycle proceeds again.

The system has a full manual bypass function. It can be operated with total safety from a control desk, located above the MCC room.