KL1501-1001 by Beckhoff

The KL1501-1001 is a Beckhoff terminal within the KL Analog Input Modules series. It captures pulse sequences from encoders or proximity switches and transfers the count value to a PLC, supporting flow, length, or quantity monitoring in automated machinery. Designed for inclusion in modular I/O stations, the terminal snaps into place beside adjacent KL terminals and communicates over the internal K-bus. This connection makes counter data available in the process image for use by the controller.

The single input channel operates as a 1 × up/down counter, so the terminal can increment or decrement its count value according to the direction signal. Count detection occurs on the incoming pulse's rising edge, and accuracy is maintained at frequencies up to 100 kHz, which suits fast encoder or turbine meter feedback. Two transistor stages provide two digital outputs for feedback or latch functions. An 8-bit control and status bus handles internal handshaking within the terminal. The module publishes five input bytes and five output bytes to the controller, mapping the count value and status information into the process image reserved for the channel. A 0x0100 feature register allows the system to identify the terminal type during startup. The input circuitry follows EN 61131-2 Type 1 requirements for signal-level compatibility.

Electrical power for the output stages is supplied by the system's 24 VDC auxiliary circuit. Four diagnostic signal LEDs on the front indicate the input state, output switching, and fault conditions. The housing provides IP20 protection and permits installation in any orientation. Mechanical attachment uses a standard 35 mm DIN rail, so no additional mounting brackets are required. Application data are exchanged over the K-bus with a width of 32 bits, giving the controller a direct numerical representation of the counter value. The modular housing also allows the terminal to be installed with other KL-series I/O devices in a compact control assembly.