Model: PCI‑6520

Part Number: 779443‑01

Brand: National Instruments (NI)

Series: 652x Industrial Isolated DIO

Bus: PCI (5 V, half‑length)

Connector: 1 × 37‑pin D‑Sub (keyed)

Isolation: Channel‑to‑channel optically isolated (8 DI); relay‑isolated (8 DO)

Driver: NI‑DAQmx

Operating Temp: 0 ~ 55 °C

Features: ±30 VDI, 60 V / 2 A relay DO, channel‑to‑channel isolation, watchdog, programmable power‑on, low cost

I. Digital Inputs (DI) – 8 ch, isolated, sink/source

• Channels: 8 channel‑to‑channel optically isolated digital inputs

• Voltage Range: ±30 VDC

• Logic Thresholds: Low ≤ +4 V, High ≥ +11 V

• Input Type: sink or source configurable (24 V logic)

• Filtering: programmable debounce filters per channel

• Functions: change detection, event counting, status monitoring

II. Relay Outputs (DO) – 8 ch, non‑latching mechanical relay

• Channels: 8 non‑latching mechanical relay outputs

• Switching Voltage: ±60 VDC / 30 Vrms max

• Switching Current: 2 A / channel max

• Switching Power: 60 W / 60 VA max

• On‑Resistance: < 100 mΩ (typical)

• Power‑On State: programmable (open / closed)

• Life Cycle: 100,000 operations (resistive load)

• Functions: load switching, emergency cut‑off, high‑voltage control

III. Industrial Features

• Watchdog Timer: 1–65535 ms; fault → safe state (open/closed)

• Programmable Power‑On: prevents unexpected actuation

• Channel‑to‑Channel Isolation: each DI isolated; relays isolate DO from system

• High CMR: robust for motors, inverters, relays

• Keyed Connector: prevents miswiring, enhances safety

IV. Physical & Environmental

• Size: half‑length PCI, ~12.4 × 12.6 × 2.2 cm

• Weight: ~0.15 kg

• Temperature: 0 ~ 55 °C (oper), −20 ~ 70 °C (storage)

• Humidity: 10%–90%, non‑condensing

• Isolation Voltage: ≥ 500 Vrms (DI channels to system ground)

• Power: +5 V @ ~200 mA; +3.3 V @ ~300 mA

V. Wiring Highlights

• DI (sink/source): sensor to +24 V or GND; threshold +4 V low / +11 V high

• Relay DO: load between relay common (COM) and normally open (NO) / normally closed (NC); max 60 V / 2 A

• Inductive loads: add 1N4007 freewheeling diode across coil

• Shielding: shield to isolated field ground, not system ground

VI. Core Advantages & Applications

• 8 channel‑to‑channel isolated DI (±30 V) + 8 relay DO (60 V / 2 A)

• True channel‑to‑channel isolation, mechanical relays, watchdog, programmable power‑on, NI‑DAQmx

• Ideal for 24 V sensor monitoring + high‑voltage/high‑current load switching, industrial control panels, test stands, safety interlocks