Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 2.423.451.00 (also referenced as 2_423_451_00) |
| Manufacturer | Entrelec Schiele (ABB Group) |
| Product Type | PMO Transistor Digital Output Module, 8-Channel |
| Compatible System | Systron PM S200 / PM S250 compact PLC/DCS |
| Output Type | Transistor (NPN/PNP configurable per rack), sinking/sourcing |
| Output Voltage Range | 20–30 V DC (rated 24 V DC) |
| Max Current per Channel | 1 A continuous |
| Total Output Current | ≤ 4 A (group-limited) |
| Switching Delay | < 1 ms (on/off typical) |
| Isolation Voltage | 3 kV AC (output group ↔ bus / power supply) |
| Bus Power Consumption | ≤ 155 mA @ 26.5–31.6 V DC (rack backplane) |
| Aux. Sensor Supply | 20–30 V DC, 100 mA, short-circuit protected |
| Operating Temperature | -20 °C to +60 °C |
| Storage Temperature | -40 °C to +85 °C |
| Humidity | 5–95 % RH, non-condensing |
| Vibration Resistance | 5–150 Hz, 0.5 g |
| Shock Resistance | 10 g (11 ms, half sine) |
| Mounting Method | Standard DIN rail (35 mm) / PM S200-S250 rack slot |
| Protection Rating | IP20 (cabinet mounted) |
| Certifications | VDE, CE |
| Weight (approx.) | 0.2 kg |
Main Features and Advantages
8-point transistor density with group isolation:
The Schiele 2.423.451.00 packs 8 × 24 V DC transistor outputs into the Systron PM single-width I/O profile, which matters on the PM S200 — a compact rack where slot count is scarce and you might have 2 DI + 1 DO + 1 AI occupying 4 slots for a small skid. The 8 points share a 4 A group fuse (internal to the PM rack’s DO fuse plan, or on the Schiele 2.423.451.00 carrier depending on sub-revision), and the whole group is 3 kV AC isolated from the backplane. That means a shorted solenoid on channel 5 won’t back-feed the PM S250 CPU or the DI brother card on the same rack — a design choice that keeps small-panel builds survivable when the electrician mis-wires a 24 V DC coil across the 230 V AC feeder by accident (yes, it happens; the Schiele 2.423.451.00 group fuse pops, the CPU stays up).
<1 ms switching with LED-per-channel:
Each of the 8 outputs on the Schiele 2.423.451.00 has a green LED on the front fascia, so a panel walkthrough answers “did the PM S250 program actually fire the output, or is the solenoid coil open?” without a laptop or a multimeter. The <1 ms on/off latency is fast enough for pulse-width tricks — marking a bottle every 200 ms on a 300 bpm packaging lane, or pulsing a reject solenoid on a weigher — though the Schiele 2.423.451.00 is not a stepper/indexer output; it’s a process DO. Still, for a compact PLC/DCS hybrid where the CPU scan is 5–10 ms, the <1 ms DO latency means the output settles well before the next scan reads the feedback DI — no “missed pulse” complaints.
Auxiliary sensor supply built in:
The Schiele 2.423.451.00 provisions a 20–30 V DC / 100 mA short-protected “sensor power” tap that the PM rack routes to the field side. On a small skid — say a packaged water-booster with three prox switches and two solenoid valves — the Schiele 2.423.451.00 can power the prox sensors from its own aux rail and switch the solenoids from the 24 V DC output rail, all from one module, no extra PSU in the panel. That’s the “compact PLC/DCS” value prop of the Systron PM line: the Schiele 2.423.451.00 isn’t just an output — it’s part of a skid-in-a-box BOM where slot count and PSU count both need to stay low.
Bus-fail output freeze:
A small but meaningful detail on the Schiele 2.423.451.00 — if the Systron PM backplane bus blips (CPU swap, rack power glitch, PMDP coupler dropout on a distributed drop), the Schiele 2.423.451.00 holds the last output state for ~1 second before defaulting to safe state. On a water-pump skid where the DO fires a “run-permit” relay to the pump VFD, that 1-second hold avoids a spurious VFD fault-trip on a harmless bus bounce. It’s not a full redundant-output safety function (the Schiele 2.423.451.00 isn’t SIL-rated), but for non-safety process loops it’s the right granularity.
Short / overload / reverse-polarity protection:
Each output channel on the Schiele 2.423.451.00 has rapid current-limiting; a sustained short on a 24 V DC solenoid (coil winding to housing ground, classic failure) trips the channel or the group fast enough that the transistor array doesn’t avalanche. Reverse-polarity on the 24 V DC field feed is also clamped — again, small-panel builds where the panel shop wired “+24” to “0V” by mistake don’t kill the Schiele 2.423.451.00 instantly; they get a grouchy LED pattern and a fuse pop, not a scrapped module.
Discontinued but supported via spare channel:
Because the Schiele 2.423.451.00 is OEM-discontinued, the “advantage” story shifts to availability: original-stock and refurb units are still in circulation, tested against PM S200/S250 racks, and the module is mechanically/electrically backward-compatible across PM S200 and PM S250 (the bus voltage 26.5–31.6 V DC and the backplane pinout are stable between the two). For plants with five PM S250 panels across three pump stations, stocking two cold-spare Schiele 2.423.451.00 covers all of them. The alternative — migrate the whole skid to a newer ABB AC500 or a Siemens S7-1200 — is a capital project; the Schiele 2.423.451.00 as a spare is the MRO economics play.
