Fit check against common peers
If your panel expects a FX2N-48ER-DS extension unit, this base unit does not drop into that slot: different form factor and bus interface. Against the FX2N-48MR-DS (48 I/O, 24 V DC), the FX2N-32MR-ES/UL offers half the I/O and demands 100-240 V AC. Both use relay outputs, so load-handling per channel is similar, but the supply rail mismatch requires a transformer swap.
16 inputs and 16 relay outputs, powered by 100-240 V AC at 40 VA.