HITACHI LYA010A

Technical Specifications

1. Channel Configuration: 8-channel Digital Input (DI) + 8-channel Relay Digital Output (DO)
2. Power Supply: Rated 24 VDC operating voltage; maximum total module current consumption ≤250mA
3. Input Electrical Parameters: DI trigger threshold 15VDC ON / 5VDC OFF; single-channel input current 5mA @24VDC; response time 1ms
4. Output Electrical Parameters: Relay contact rated load 5A @24VDC resistive load; maximum switching frequency 10Hz; mechanical relay service life ≥10,000,000 operations
5. Isolation Performance: 1500VAC opto-isolation between field side and internal logic bus, per channel independent isolation
6. Environmental Parameters: Operating temperature -25°C ~ +55°C; storage temperature -40°C ~ +70°C; relative humidity 5%–95% non-condensing
7. Protection Grade: Front panel IP20; PCB internal conformal coating for anti-dust and anti-moisture
8. Physical Dimensions: Standard single-slot Eurocard rack form factor; weight 0.42kg
9. Communication Interface: Backplane parallel bus communication compatible with Hitachi L Series main controllers

Function Features

1. Dual-function mixed I/O architecture integrates signal acquisition and load drive to reduce rack slot occupation quantity
2. Independent green LED status indicator per DI/DO channel for real-time on-site fault diagnosis without auxiliary testing tools
3. Built-in RC absorption circuit at relay output terminals to suppress surge voltage generated by inductive loads (solenoid valves, contactors)
4. Polarity reverse protection circuit on all digital input channels to avoid permanent damage from miswiring field sensors
5. Hot-pluggable hardware design; module replacement does not require full rack power shutdown
6. Onboard hardware self-diagnosis circuit; backplane transmits channel short-circuit, open-circuit and over-current fault codes to main CPU automatically

Performance Parameters

• Full-scale signal sampling accuracy: 100% digital switching threshold without drift
• Long-term temperature drift: <0.2% full range within rated operating temperature band
• Electromagnetic compatibility compliance: IEC 61000-6-2 industrial heavy EMC standard
• Vibration resistance: 10–150Hz, 1.5mm amplitude continuous operation without signal loss

Material Composition

1. Main Circuit Board: FR-4 high-temperature resistant flame retardant PCB with full tin plating copper traces
2. Isolation Components: High-speed industrial optocoupler chips with reinforced insulation encapsulation
3. Output Switching Components: Silver alloy contact miniature electromagnetic relays
4. Housing & Pull Tab: Cold-rolled steel front panel with electrostatic spraying; PA66 glass fiber reinforced plastic locking pull tab
5. Terminal Connector: Gold-plated copper multi-pin backplane male connector, corrosion-resistant

Structural Features

1. Single-slot horizontal plug-in structure matching Hitachi standard 19-inch control rack
2. Dual side mechanical locking pull tabs to prevent loose contact under strong vibration environments
3. Detachable front wiring terminal block; wiring harness remains connected during module disassembly
4. Layered circuit layout: logic circuit layer isolated from field signal circuit layer via ground separation copper strips
5. Uniform ventilation slot design on front panel for passive heat dissipation of relay components

Working Principle

1. Digital Input Path: Field 24VDC switching signal passes through polarity protection circuit, optocoupler isolation, and signal shaping circuit, then transmits standard TTL level digital signals to rack backplane bus for CPU reading
2. Digital Output Path: Main controller sends switching commands via backplane bus; internal drive chip triggers relay coil actuation; relay contacts conduct or disconnect external 24VDC load circuits; RC absorption circuit eliminates inductive surge during contact switching
3. Self-Diagnosis Mechanism: Real-time current sampling on each channel; abnormal current triggers fault flag uploaded to central control unit for alarm processing

Advantage Highlights

1. Mixed DI+DO integrated design cuts rack space occupation by 50% compared to separate single-function input/output cards
2. Full-channel independent opto-isolation eliminates cross-channel signal crosstalk in high-frequency electromagnetic interference environments
3. Relay output supports large-current resistive loads, eliminating external intermediate relay requirements for most on-site actuators
4. Wide temperature operating range adapts to unheated industrial workshop and semi-outdoor control cabinet deployment
5. Hot-swap maintenance drastically reduces system downtime during on-site module failure replacement
6. Full compliance with global industrial EMC standards without additional external signal filtering modules

Applicable Industries

Installation Requirements

1. Mount exclusively on Hitachi original standard L-series PLC 19-inch Eurocard rack; single slot installation without overlapping adjacent modules
2. Maintain minimum 10mm vertical ventilation gap above and below the module inside control cabinet
3. Field wiring must use shielded twisted pair cables; shield layer single-point grounded at cabinet earth bar
4. External load wiring maximum wire cross-section 1.5mm²; terminal screw tightening torque fixed at 0.8 N·m
5. Cabinet internal ambient temperature must not exceed +55°C; forced air cooling required if cabinet heat load exceeds rated limit

Usage Notes

1. Inductive loads (solenoid valves, AC contactors) must use built-in RC absorption circuit; do not remove original absorption components
2. Relay contact load current strictly limited to ≤5A; parallel external relay required for loads exceeding rated current
3. Prohibit reverse connection of 24VDC power supply to backplane bus; power cut before plugging/unplugging if hot-swap function is disabled
4. Regular quarterly inspection of terminal block wiring tightness to prevent oxidation-induced signal open circuits
5. Storage environment must maintain humidity below 80%; seal with desiccant for long-term idle storage
6. Do not clean PCB circuit board with liquid solvent; compressed air (dry, oil-free) only for dust removal