Description
Pearl-MM is a PC/104 format industrial control module with 16 relays. The relays have PDT (form C) configuration. Each relay has 3 contacts: Common, Normally Open, and Normally Closed. For safety and reliability, all relays are in their power-off state (Common connected to Normally Closed) at power-up or system reset. The relays can switch both AC and DC voltages. They feature long life (100,000,000 operations), quick actuation time (4ms max operate and release), and isolation (500V AC or DC).

I/O Headers
C = Common>

NC = Normally Closed (connected to Common when relay is not energized)

NO = Normally Open (connected to Common when relay is energized)

Pearl-MM is programmed using two 8-bit I/O registers. Each bit controls one relay. Writing a 1 to a bit turns the relay on, while writing a 0 turns the relay off. On power-up or reset, all bits are 0, and all relays are off (C connected to NC).