Description
Key Technical Specifications
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Model Number: 1C31169G02
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Manufacturer: Emerson (formerly Westinghouse)
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Function: 32-channel digital input module – sinking inputs for 24 VDC field devices
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Input Channels: 32 isolated sinking inputs, 18-30 VDC wetting, grouped in 4 banks of 8
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Response Time: <5 ms typical edge detection
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Isolation: 2 kV channel-to-bus; 500 V bank-to-bank
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Diagnostics: Per-channel LED status, open-circuit detection
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Power Supply: 24 VDC from Ovation back-plane; <3 W typical
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Operating Temperature: 0…+60 °C
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Mounting: Plug-in to Ovation base-plate (e.g., 1C31166G01) – hot-swap supported
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Dimensions / Weight: 121 × 52 × 166 mm, 0.56 kg typical
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Certifications: CE, UL, CSA, IEEE 323/384 (nuclear qualified configurations)
- Status: Factory discontinued – new & tested spares available
1C31169G02
Field Application & Problem Solved
In the field the biggest headache is landing thirty-two digital signals—turbine trip relays, breaker auxiliaries, valve limit switches—without stuffing multiple cards in the rack and still meeting <5 ms response times. The 1C31169G02 solves that by giving you thirty-two 24 VDC sinking inputs in one slot: it detects an edge in <5 ms, time-stamps it for SOE, and pushes the data onto the 30 kHz carrier. You’ll typically find one per protection panel on Frame-7/9 peakers—swap time is under two minutes with the unit on turning gear. Core value: it collapses thirty-two isolated inputs, surge protection, and per-channel diagnostics into one 0.56 kg plug-in card you can hot-swap without losing a single event.
In the field the biggest headache is landing thirty-two digital signals—turbine trip relays, breaker auxiliaries, valve limit switches—without stuffing multiple cards in the rack and still meeting <5 ms response times. The 1C31169G02 solves that by giving you thirty-two 24 VDC sinking inputs in one slot: it detects an edge in <5 ms, time-stamps it for SOE, and pushes the data onto the 30 kHz carrier. You’ll typically find one per protection panel on Frame-7/9 peakers—swap time is under two minutes with the unit on turning gear. Core value: it collapses thirty-two isolated inputs, surge protection, and per-channel diagnostics into one 0.56 kg plug-in card you can hot-swap without losing a single event.
Installation & Maintenance Pitfalls (Expert Tips)
24 V Wetting Must Be Isolated – Don’t Double-Ground
The module is sinking; it expects the field device to source 24 V. If you land a wet contact that is already grounded you’ll create a ground loop and the input LED flickers. Verify wetting supply isolation with a megger before you land the wires.
The module is sinking; it expects the field device to source 24 V. If you land a wet contact that is already grounded you’ll create a ground loop and the input LED flickers. Verify wetting supply isolation with a megger before you land the wires.
Per-Channel LED Lies If the Opto Is Dead
Green LED only means the opto LED is lit; if the opto transistor fails the CPU still sees “input high” even if the field contact is open. Meter the D-Sub pins during a test—if you don’t see the transistor pull low, replace the module.
Green LED only means the opto LED is lit; if the opto transistor fails the CPU still sees “input high” even if the field contact is open. Meter the D-Sub pins during a test—if you don’t see the transistor pull low, replace the module.
Hot-Swap Only with Field Power Off – Contacts Are Live
The module is hot-swappable but the 24 V field terminals are exposed. If you pull it while a coil is energized you’ll arc the stab pins. Open the field breaker first or you’ll weld the back-plane connector.
The module is hot-swappable but the 24 V field terminals are exposed. If you pull it while a coil is energized you’ll arc the stab pins. Open the field breaker first or you’ll weld the back-plane connector.
Spare Lead-Time Is 6-8 Weeks – Keep One on the ShelfFactory stock is gone; new & tested spares are available but not overnight. If you crack a layer or burn the opto you’ll be down until the part arrives—keep one in stores or you’ll discover the weakness during the next grid event.
Technical Deep Dive & Overview
Internally the module is a 32-channel opto-isolator array bolted to a 2 kV isolation barrier. Each input drives an LED that latches the edge; the 30 kHz carrier clocks the data into the Ovation back-plane. Lose the 24 V rail and the module goes dark; lose a single input and the CPU throws “DI FLT” for that channel only. No firmware to reload—pure hardware—so you can hot-swap it: pull the old card, land the field wires exactly where they came from, snap the 96-pin connector in, and the DCS sees all thirty-two inputs again in under ten seconds.
Internally the module is a 32-channel opto-isolator array bolted to a 2 kV isolation barrier. Each input drives an LED that latches the edge; the 30 kHz carrier clocks the data into the Ovation back-plane. Lose the 24 V rail and the module goes dark; lose a single input and the CPU throws “DI FLT” for that channel only. No firmware to reload—pure hardware—so you can hot-swap it: pull the old card, land the field wires exactly where they came from, snap the 96-pin connector in, and the DCS sees all thirty-two inputs again in under ten seconds.
