Industry began using programmable limit switches (PLS) as a direct replacement for mechanical cam switches because they are easier to set up, and changes can be made quickly and easily. However a major drawback of the stand-alone PLS was that communicating with the PLC was difficult. AMCI changed all of that by developing PLS modules for the SLC-500. These programmable limit switch modules provide the high-speed switching capability of a PLS in combination with direct communication with the PLC.

AMCI has created several versions of the programmable limit switch module. The 2541 provides 6 high speed inputs and outputs directly connected to the module. The 8500 series modules contain up to 16 high speed I/O as well as 16 additional outputs through the module's backplane connection to the PLC. Each module has such necessary features as speed compensation, output ANDing, and output enable/disable. Whether its gluing, sealing, stamping, or assembling, each module has specific features to make programming and implementation quick and easy.