HITACHI LYD000A

Technical Specifications

1. Channel Count: 8 independent isolated digital input channels
2. Nominal Input Voltage: 24 VDC; operable input range 12VDC ~ 30VDC
3. Single Channel Input Current: 5mA @ rated 24VDC input voltage
4. Switch Threshold: ≥15VDC = ON state; ≤5VDC = OFF state
5. Isolation Strength: 1500VAC channel-to-logic optoelectronic isolation
6. Response Time: Maximum 1ms signal switching delay (OFF→ON / ON→OFF)
7. Operating Temperature Band: -20°C ~ +70°C; storage temperature -40°C ~ +85°C
8. Humidity Rating: 0%–95% relative humidity, non-condensing
9. Protection Class: Front panel IP20
10. Backplane Bus: Hitachi proprietary parallel rack bus, single-slot occupation

Function Features

1. Universal sink/source dual wiring mode support, compatible with all industry standard NPN/PNP field sensors
2. Independent green LED status indicator for every input channel, visual real-time signal status feedback
3. Hardware polarity reverse protection on all input terminals, zero damage risk from miswiring positive/negative poles
4. Built-in low-pass noise filtering circuit on each channel to suppress high-frequency pulse interference from inverter and motor equipment
5. Hot-swappable rack plug-in design, supporting online maintenance without system full power shutdown
6. Embedded channel open-circuit self-test function; fault information uploaded to main CPU via backplane bus automatically

Performance Parameters

• Signal sampling resolution: Binary digital switching signal without analog measurement drift
• EMC Compliance: IEC 61000-6-2 heavy industrial electromagnetic interference standard
• Vibration endurance: Continuous operation under 10–200Hz vibration without signal misjudgment
• Long-term isolation stability: Insulation resistance ≥1000MΩ after 5 years continuous field operation

Material Composition

1. Substrate: FR-4 flame retardant high-temperature PCB with conformal moisture-proof coating
2. Isolation Device: Reinforced insulation industrial optocoupler chips per independent channel
3. Front Panel: Cold-rolled steel electrostatic anti-corrosion spray coating
4. Locking Hardware: Glass fiber reinforced PA66 plastic pull tabs with stainless steel spring latches
5. Terminal Connectors: Gold-plated copper multi-pin detachable wiring terminal block

Structural Features

1. Standard single-slot Eurocard horizontal rack installation form factor
2. Dual mechanical locking pull tabs on left and right sides for anti-loosening under high vibration
3. Separable front wiring terminal block; field wiring harness retains connection during module replacement
4. Partitioned circuit layout: Field signal area completely separated from backplane logic bus area via isolation barrier
5. Passive heat dissipation ventilation slits evenly distributed on front panel surface

Working Principle

1. Field 24VDC switching signal enters channel protection circuit first to block reverse voltage and surge pulse interference
2. Filtered signal drives optocoupler to realize electrical isolation between field side and internal logic circuit
3. Optocoupler output converts analog voltage signal into standard TTL digital level, transmitted to backplane bus for main controller reading
4. Built-in current sampling circuit monitors channel conduction status continuously; abnormal open-circuit triggers fault alarm signal transmission

Advantage Highlights

1. Universal NPN/PNP dual wiring eliminates the need for two separate input module models for different sensor types
2. Ultra-fast 1ms response time meets high-speed position counting and rapid equipment interlock signal acquisition demands
3. Full-channel independent isolation prevents single-channel field surge from damaging entire control rack backplane
4. Wide operating temperature range supports deployment in metallurgy, thermal power and other high-temperature industrial cabinet environments
5. Detachable terminal block reduces wiring modification workload during on-site system upgrade

Applicable Industries

Installation Requirements

1. Install into original Hitachi L-series control rack single slot only; maintain ≥10mm vertical ventilation clearance with adjacent modules
2. Field sensor wiring adopts shielded twisted pair cable; shielding layer single-point grounded at cabinet earth terminal bar
3. Terminal wiring wire cross-section limited to maximum 1.5mm²; terminal screw torque controlled at 0.8 N·m
4. Control cabinet equipped with temperature exhaust fan if internal ambient temperature exceeds 60°C
5. Rack backplane power supply must provide stable 24VDC ±5% voltage fluctuation range

Usage Notes

1. Strictly prohibit input voltage exceeding 30VDC to avoid permanent breakdown of optocoupler isolation components
2. Do not share common ground wire between field sensor negative pole and control cabinet protective earth to prevent ground loop noise
3. Conduct annual insulation resistance testing of input channels using 1000V megohmmeter
4. Dry oil-free compressed air only for dust removal on PCB; liquid cleaning agents are forbidden
5. Store spare modules in sealed packaging with desiccant at humidity ≤70%