PLS vs PLC

A programmable limit switch provides outputs that remain ON for a programmed position dwell. A PLC can perform the same function by reading position from a position-input module, and then comparing the position  with user-set limits and turning ON output if the position is within limits. However, the timings of the outputs  will vary by the scan time of the PLC, which is not acceptable in many applications. The PLS module from  AVG-Autotech offers many advantages over the PLC as far as  PLS function is concerned:

1. The PLS module provides highly repeatable outputs independent of PLC scan time.
2. With PLS module, you do not have to write any software in PLC to perform PLS functions.
3. The PLS module makes it extremely easy to fine-tune dwells while the machine is in motion.
4. Advanced features of PLS module, such as speed compensation, require complex coding when  implemented in PLC, particularly in ladder logic.