The Schneider TM2DMM8DRT discrete I/O module is part of the Modicon M238 logic controller family and is now obsolete. It gives you four 24 VDC inputs (sink or source, 7 mA draw) and four relay outputs (normally open, rated 2 A per channel on resistive loads). The input side accepts 20.4–28.8 VDC and pulls 20 mA from the 24 V rail when all channels are on. Common points are one for inputs and one for outputs, with the output common carrying up to 7 A total.
Fit and integration notes
I/O mapping is straightforward: 4 inputs (sink or source, 3.4 kOhm impedance) and 4 relay outputs (NO contacts, 45 mOhm contact resistance). Minimum switching is 0.1 mA at 0.1 VDC, so it handles dry-contact-level signals. Input response time is 4 ms per transition. Isolation is 500 V between input and internal logic, 1500 V between input and output groups, and 2300 V on the output side — solid for separation between 24 V field wiring and backplane. Mechanical durability is 20 million cycles; electrical endurance varies by load — 100,000 cycles at 1 A AC-15 (240 V, cos phi 0.7) or 100,000 cycles at 1 A DC-13 (24 V, inductive). For resistive loads at 2 A, expect 100,000 cycles as well.