Description
Key Technical Specifications
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Model Number: 1C31234G01
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Manufacturer: Emerson (formerly Westinghouse)
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I/O Configuration: 16 digital inputs + 16 digital outputs (expandable to 32 each)
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Input Signal: Dry contact or 12-48 VDC wet contact (NPN/PNP selectable)
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Output Signal: Relay contact, 5 A resistive / 2 A inductive, 250 V AC / 30 V DC max
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Response Time: ≤1 ms input detection, ≤2 ms relay action
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Isolation: 2500 V AC channel-to-channel, 1500 V AC power-to-bus
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Supply Voltage: 5-24 VDC field power; 220 VAC bus power from Ovation rack
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Power Consumption: 18 W typical
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Operating Temperature: –40…+85 °C
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Protection / Safety: Over-current, over-voltage, short-circuit, SIL 2 certified
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Communication: Modbus-RTU (RS-485), Profibus-DP, EtherNet/IP (jumper-selectable)
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Mounting: DIN-rail or 19-inch sub-rack; hot-swappable
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Dimensions / Weight: 157 × 79 × 31 mm module, 0.2 kg
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Status: Factory discontinued – new & tested spares available
1C31234G01
Field Application & Problem Solved
In combined-cycle plants the biggest headache is landing sixteen digital signals—trip relays, breaker auxiliaries, valve limit switches—without stuffing multiple cards in the rack and still meeting SIL 2 response times. The 1C31234G01 solves that by giving you sixteen high-speed inputs plus sixteen relay outputs in one base: it detects a contact change in ≤1 ms, time-stamps it for SOE, and drives a 5 A trip relay in ≤2 ms. 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 sixteen isolated inputs, sixteen relay outputs, surge clamps, and SIL 2 diagnostics into one 0.2 kg hot-swap module you can bolt to the skid without pulling new cable.
In combined-cycle plants the biggest headache is landing sixteen digital signals—trip relays, breaker auxiliaries, valve limit switches—without stuffing multiple cards in the rack and still meeting SIL 2 response times. The 1C31234G01 solves that by giving you sixteen high-speed inputs plus sixteen relay outputs in one base: it detects a contact change in ≤1 ms, time-stamps it for SOE, and drives a 5 A trip relay in ≤2 ms. 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 sixteen isolated inputs, sixteen relay outputs, surge clamps, and SIL 2 diagnostics into one 0.2 kg hot-swap module you can bolt to the skid without pulling new cable.
Installation & Maintenance Pitfalls (Expert Tips)
Relay Contacts Are 5 A Resistive – Don’t Over-Fuse
The Form-C contacts are silver-alloy rated 5 A resistive / 2 A inductive. If you protect the load with a 10 A fuse the contacts will weld before the fuse blows. Use 5 A fast-acting fuses or you’ll chase “relay stuck” faults that aren’t the module’s fault .
The Form-C contacts are silver-alloy rated 5 A resistive / 2 A inductive. If you protect the load with a 10 A fuse the contacts will weld before the fuse blows. Use 5 A fast-acting fuses or you’ll chase “relay stuck” faults that aren’t the module’s fault .
Hot-Swap Only with Power Off – Contacts Are Live
The module is hot-swappable but the relay contacts carry field power. If you pull it while the contactor 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 relay contacts carry field power. If you pull it while the contactor coil is energized you’ll arc the stab pins. Open the field breaker first or you’ll weld the back-plane connector.
48 V Wetting Supply Must Be Isolated – Don’t Double-Ground
The module sources 48 V for dry contacts. 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 sources 48 V for dry contacts. 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.
Spare Lead-Time Is 6-8 Weeks – Keep One on the Shelf
Factory stock is gone; new & tested spares are available but not overnight. If you burn a relay or crack a layer you’ll be down until the part arrives—keep one in stores or you’ll discover the weakness during the next grid event.
Factory stock is gone; new & tested spares are available but not overnight. If you burn a relay or crack a layer you’ll be down until the part arrives—keep one in stores or you’ll discover the weakness during the next grid event.
1C31234G01
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 opto-coupler that latches the edge; each output drives a 5 A relay with MOV snubbers. The FPGA handles the ≤1 ms scan and posts the data over Modbus-RTU or Profibus-DP. Lose the 24 V field supply and the inputs go dead; lose the 220 VAC bus and the whole module browns out. No firmware to reload—pure hardware—so you can hot-swap it: pull the old module, land the field wires exactly where they came from, snap the DIN-rail latch, and the DCS sees all 32 I/O 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 opto-coupler that latches the edge; each output drives a 5 A relay with MOV snubbers. The FPGA handles the ≤1 ms scan and posts the data over Modbus-RTU or Profibus-DP. Lose the 24 V field supply and the inputs go dead; lose the 220 VAC bus and the whole module browns out. No firmware to reload—pure hardware—so you can hot-swap it: pull the old module, land the field wires exactly where they came from, snap the DIN-rail latch, and the DCS sees all 32 I/O again in under ten seconds.
