Mitsubishi QD62D – two high-speed counter channels on a single Melsec Q bus module. Each input accepts differential RS422A signals at 5/12/24 VDC (2–5 mA) and counts up to 500 kHz. The internal 32-bit signed register spans –2,147,483,648 to +2,147,483,647, so it handles long position or velocity accumulations without rollover worry. Dedicated preset and function-start digital inputs (total 16 I/O points on the front) let you trigger resets or gate the count without burning extra input slots on the base rack. Power draw is 380 mA from the 5 V backplane – modest, but tally it against your Q bus budget if the rack is near its limit.
Integration notes
Connects via a 40-pin front connector; signal wiring uses 0.3 mm² wire. Dimensions: 2.74 cm x 9.8 cm x 9 cm.