Sumtak FHH651AAAB Pulscale is a digital linear encoder/scale unit used in industrial motion control systems to provide precise position feedback. Common failure modes for this class of encoders include mis‑alignment or damage to the scale surface, power supply voltage drops or spikes, shorted or open signal lines, and firmware corruption that can cause erroneous counts or loss of communication. Initial diagnostics should verify that the unit receives its rated supply voltage and that all ground connections are secure; check the encoder output signals with an oscilloscope for continuity and proper logic levels; and review any error codes or status LEDs on the controller interface to isolate whether the issue is mechanical, electrical, or software‑related.[oss-gpt-20b]