The Mitsubishi QD60P8-G is an inter-channel isolated pulse input unit designed for high-speed counting in PLC applications. It provides 8 independent channels that accept 1-phase pulse signals, configurable for counting speeds from 0.1 pps up to 30 kpps. Each channel can handle pulse trains at either 5 VDC or 12–24 VDC signal levels, making it compatible with a range of incremental encoders and pulse generators. The module occupies 32 I/O points on the backplane and draws 0.58 A from the 5 VDC rail. Internal count values are held in 32-bit registers, with a maximum input pulse value of 2,147,483,647.
What the ratings mean for fit
The 8-channel capacity covers multi-axis encoder feedback or batch counting from several sensors. The counting speed range, settable via parameter from 0.1 pps to 30 kpps, lets you match the module to the signal frequency: use 30 kpps for fast incremental encoders on linear scales, drop to 100 pps for slow flow-meter pulses. The corresponding minimum pulse width at 10 kpps is 100 µs (50 µs ON/OFF), so check encoder duty cycle. Isolation is channel-to-channel and channel-to-ground: withstand voltage between channel pairs is AC 1780 V 1 min, and between AC external terminal and ground is AC 1500 V 1 min. This protects the PLC backplane from field wiring transients.