What it does on the backplane
The Omron CS1D-PD025 is a power supply module that drops onto the CS1D backplane and converts a 24VDC input into a regulated 5VDC rail at 5.3A, which is the headline 40W output capacity the rack draws from to feed CPU and I/O modules. Input is DC-only at 24VDC, so this is the module to specify where panel supply is already 24V battery or 24VDC PSU-derived, not where mains AC is the only rail available. Approvals on the nameplate are CE, cULus, Lloyd, and NK, covering the common North American, European, and marine-classification paths a panel shop and a ship-systems integrator both need to clear.
Output envelope and what the 40W number actually means
The 40W figure is the rated continuous output at 5VDC and 5.3A, so the rack budget before this supply clips is the sum of every CS-series module's 5V draw — stay inside that envelope and the CS1D-PD025 sits comfortably; exceed it and you either shed I/O or step up to a higher-capacity supply. The CS1D-PA207R is the AC-input counterpart in the same CS1D family, accepting 100–120VAC or 200–240VAC and delivering 5VDC at 7A / 35W, which is a different power-class choice rather than a substitute for the DC-input CS1D-PD025.
Lifecycle and supply posture
Production status is recorded as Active, so the CS1D-PD025 is the current CS-series backplane supply rather than a last-time-buy part — quote-to-order against the BOM line remains the working supply channel.