PCI-6515 | Product Overview

The NI PCI-6515 is a National Instruments (NI) industrial-grade 64-channel isolated DIO (32 isolated inputs + 32 isolated emitter outputs, ±30 V, 8 groups of isolation, high current), PCI bus, half-length card, featuring:

32 isolated DI (Sink/Source compatible, ±30 V, 12.5 mA) + 32 isolated DO (Sink, 120 mA per channel, peak 500 mA, 8 groups of independent optocouplers, watchdog, programmable power-on state) NI

Suitable for 24 V sensors / proximity switches / button inputs + relays / solenoids / LED outputs (negative logic), factory automation, mixed switch quantity control in strong interference environments.

Part number: 778835-01; discontinued (EOL), replacement model: PCIe-6515.

I. Basic Information

Model: PCI‑6515

Brand: National Instruments (NI)

Series: 651x Industrial Isolated DIO Series

Bus: PCI (5 V compatible, half-length card)

Connector: 1 × 100-pin SCSI (high density)

Isolation: 64 channels divided into 8 groups (Bank 0–7, each group 8 channels: 4 DI + 4 DO), optical isolation between groups. NI

Driver: NI‑DAQmx

Operating Temperature: 0 ~ 55 °C

Features: ±30 V withstand voltage, 8 groups of isolation, 32 DI + 32 DO, large current sink output, programmable input filtering, watchdog, programmable power-on state, high anti-interference NI

II. Digital Input DI (32 channels, isolated type, Sink/Source compatible)

Channels: 32 isolated digital inputs, 8 groups × 4 channels/group

Input Voltage Range: ±30 VDC (compatible with 5/12/24 V industrial logic) NI

Input Current: 12.5 mA/channel (maximum, 30 V input)

Input Type: Sink/Source compatible (NPN/PNP sensors can be connected) NI

Logic Levels:

High Level: ≥ +2 V (typical +5 ~ +30 V)

Low Level: ≤ +0.8 V (typical 0 ~ ‑30 V)

Input Filtering: Programmable (software debounce, eliminates spikes / contact jitter) NI

Maximum Input Rate: Approximately 1 MHz (software dependent)

Functions: Single-point reading, group reading, rising/falling edge detection, counter triggering

III. Digital Output DO (32 channels, isolated type, Sink output)

Channels: 32 isolated digital outputs, 8 groups × 4 channels/group

Output Voltage Range: 0 ~ +30 VDC (Sink output, low active) NI

Load Current:

Continuous: 120 mA/channel

Peak (pulse): 500 mA/channel

Output Type: Sink (pull-up / pull-down), output low level to ground NI

On-Resistance: Low resistance, typical < 1 Ω

Power-On State: Programmable (high / low / hold) NI

Maximum Switching Rate: Approximately 100 kHz (software dependent)

Functions: Single-point control, group control, pulse output, PWM (software), fail-safe shutdown

IV. Industrial Characteristics

Watchdog Timer: Programmable timeout (1–65535 ms), automatically switches to safe output (high / low) when a fault occurs (NI)

Programmable Power-On State: Prevents accidental actions during power-on NI

Programmable Input Filtering: Software debounce, suitable for mechanical switches / relays NI

Group Independent Isolation: 8 groups completely independent, can connect to different voltage domains, suppress ground loop interference NI

High Common-Mode Suppression: Suitable for motor, frequency converter, relay, etc. with strong interference fields

Overcurrent / Overvoltage Protection: Single-channel current limiting, prevents short circuit damage

V. Physical and Environmental

Size: Half-length PCI, approximately 12.4 cm × 12.6 cm × 2.2 cm

Weight: Approximately 0.15 kg

Temperature: 0 ~ 55 °C (operating), -20 ~ 70 °C (storage)

Humidity: 10% ~ 90%, no condensation

Isolation Voltage: ≥ 500 Vrms (between groups / to ground)

Power Consumption: +5 V @ 150 mA; +3.3 V @ 300 mA (typical)

VI. Installation and Usage Tips Installation

Power off and disconnect the power supply; insert the standard PCI half-length slot; after powering on, identify in MAX mode, and install NI-DAQmx.

Wiring (100-pin SCSI)

8 independent isolated grounds: Each group of grounds is isolated from the system ground to avoid ground loops.

DI wiring: NPN sensors (Sink) → Connect the signal to DI, and connect the sensor ground to this group of isolated grounds; PNP sensors (Source) → Connect the signal to DI, and connect the positive pole of the sensor to +24 V.

DO wiring (Sink): Positive pole of the load connects to +24 V, negative pole connects to DO; When the DO output is low, the current flows from +24 V → load → DO → isolated ground of the board.

Load voltage: 0 - 30 VDC, recommended 24 V industrial standard.

Do not short circuit: Single channel current limiting, prolonged short circuit will trigger protection.

Inductive loads (relays / solenoids): It is necessary to parallel a shunt diode (1N4007) to prevent reverse high voltage from breaking the board.

Software configuration (NI-DAQmx)

DI: Enable input filtering (debouncing 5 - 20 ms), suitable for mechanical switches.

DO: Drain output, power-on high level (safe default), watchdog 100 - 500 ms safe high level.

Output rate: Relay control is recommended ≤ 10 Hz to avoid contact burnout.

Notes

8 independent isolated groups, group-to-group withstand voltage ≥ 500 Vrms, can be mixed with different voltage DI/DO.

Long lines use shielded cables, shield connects to this group of isolated grounds, do not connect to the system ground.

Not suitable for directly connecting > 30 V loads, need to add intermediate relays for conversion.

Inductive loads must add shunt diodes, otherwise they are prone to damage the output channel.

Seven. Core features

32 isolated DI (±30 V, Sink/Source compatible, 12.5 mA, programmable filtering) + 32 isolated DO (Sink, 120 mA / channel, peak 500 mA) NI

PCI half-length card, 100-pin SCSI, NI-DAQmx, 8 independent optocouplers, watchdog, programmable power-on / filtering, high anti-interference NI

Directly connect 24 V sensors / switches + relays / solenoids / LEDs (negative logic), mixed DIO for strong interference sites, factory automation I/O station

Applicable: 32 input 32 output isolated control, sensor acquisition + actuator drive (negative logic), production line I/O, relay control cabinet, DIO in strong interference environment