Product Description:

The KSM 121 is a safety logic module manufactured by Kollmorgen within the KSM Safety Solution Modules series. Installed inside a control cabinet, it monitors one drive axis and combines encoder feedback with field I/O to trigger safe torque off and enforce speed or position limits when operating thresholds are exceeded. That arrangement allows the module to evaluate motion data together with external safety devices in the same control path. Its housing measures 22.5 mm in width, 115 mm in depth, and 100 mm in height, so it fits a single slot on a standard DIN rail and still leaves room for neighboring modules.

The input section operates from 24 VDC and draws up to 20 mA per channel, allowing direct connection to conventional safety sensors. Internal consumption of 2.4 W helps keep heat buildup low in tightly packed panels. The unit has 12 safe digital inputs for emergency-stop buttons, light curtains, gate switches, and other interlocks. To control contactors or safe drives, it also provides 8 OSSD channels with pulsed test signals for short-circuit detection. The plastic enclosure weighs 210 g and uses removable spring terminals, which supports compact wiring layouts and straightforward field connections.

Encoder processing covers sin/cos frequencies up to 200 kHz and HTL incremental signals up to 10 kHz, supporting both high-resolution position evaluation and standard pulse feedback. When used as an SSI master, the module clocks the sensor at 150 kHz; in slave mode, it accepts an incoming clock up to 250 kHz. Front connectors accept SSI, sin/cos, or TTL incremental encoders, while the top terminals connect Proxi-Switch or HTL feedback. This mix of interfaces allows the module to work with both newer encoder systems and established feedback devices. The single-axis design keeps signal handling focused on one motion channel without requiring a larger housing footprint.