What this TM3DI8A does
8-channel discrete input module from the Modicon TM3 family for 120 V AC signals. Each input draws 7.5 mA with response times of 25 ms on and 30 ms off. The module is powered from the backplane bus, so no separate supply needed. Isolation between channels and bus is 1500 V AC, which keeps line transients off the CPU side.
Snaps onto standard TH35-15 or TH35-7.5 DIN rail—no tools needed. If you're panel-mounting, the fixing kit works. The removable screw terminal block accepts 0.2 to 2.5 mm² solid wire (AWG 24 to 14), pitch 5.08 mm, so you can pre-wire the harness and drop the module in last. Width is 1.08 inches (27.4 mm)—takes up one slot in the TM3 rack. Depth is 3.3 inches (84.6 mm), so plan your cabinet depth accordingly. There's a green LED per channel for input status, handy when you're walking the route and need to see which signal is pulled in.
Rated for 15 gn shock at 11 ms, vibration up to 3 gn on DIN rail, and ambient temps from -10 to 55 °C horizontal mounting. Pollution degree 2—fine for a conditioned panel even near rotating gear. IP20 means keep it inside the enclosure, not out in the splash zone. MTBF is 410 years at 40 °C—the relays on your motor contactor will wear out long before this board does.