The AJ65SBTB1-32D is a 32-point digital input module rated for 24 VDC nominal, with an operating window from 19.2 to 26.4 VDC and a ripple limit of 5% — so it stays in spec even on a lightly loaded or long-run 24 V supply that sags under full load. Each channel draws approximately 7 mA at rated voltage; that's the per-point load the field-side power supply must budget for when all 32 inputs are active simultaneously. Isolation is via photocoupler — no galvanic transformer, but the optical barrier breaks ground loops between the field wiring and the backplane bus, which is the standard approach for 24 VDC discrete I/O in a machine control cabinet.
For a panel OEM wiring 32 field sensors, the 7 mA per-channel draw means a single 24 VDC supply rated at 0.5 A can feed the module plus a reasonable cable drop; no separate high-current bus needed.
Peer comparison: NZ2EX2B1-16D
The NZ2EX2B1-16D is a 16-point DC input module (half the point count) with a tighter voltage tolerance (20.4 to 28.8 VDC) and slightly lower per-channel draw at 6.0 mA typical. The AJ65SBTB1-32D has twice the I/O density in a similar footprint — 32 points vs 16 — so it fits a panel that needs more inputs per slot without increasing the DIN-rail real estate. The NZ2EX2B1-16D does not support multiple extension modules, while the AJ65SBTB1-32D is part of a modular remote I/O system that can be expanded; check the specific bus architecture before swapping one for the other.