Comprehensive Product Summary: ADLINK PCI-7256 / PCIe-7256
16-Channel Latching Relay Output & 16-Channel Isolated Digital Input Card

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### 1. Product Overview

Product Name: PCI-7256
Model: PCI-7256 (PCI version) / PCIe-7256 (PCI Express version)
Series: NuDAQ® Digital I/O Series
Article Number: PCI-7256
Manufacturer: ADLINK Technology Inc.
Website: [www.adlinktech.com](http://www.adlinktech.com)

The ADLINK PCI-7256 is a high-performance digital I/O interface card designed for industrial automation, laboratory control, and general-purpose on/off device management. It provides 16 latching SPDT (Form C) relay outputs and 16 optically isolated digital inputs, offering robust electrical isolation, reliable switching, and power-saving latching relay technology. The PCIe-7256 variant provides identical functionality on a PCI Express x1 interface.

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### 2. Key Features

- Bus Interface:
- PCI-7256: 32-bit, 3.3V/5V PCI bus, Plug and Play compliant
- PCIe-7256: PCI Express x1, Plug and Play compliant

- Relay Outputs:
- 16-channel latching SPDT (Form C) relays
- Output state retained when power is off (latching mechanism)
- Power-saving relay actuation design
- Onboard and external LED indicators for relay status

- Digital Inputs:
- 16 optically isolated, non-polar digital input channels
- 24V input range, with optional RC filtering
- Change-of-State (COS) interrupt detection on all channels
- Dedicated interrupt sources on channels 0 and 1

- Isolation & Protection:
- 2500 V RMS isolation (input-to-system)
- 1500 V RMS isolation (relay contacts)
- Robust design for noisy industrial environments

- Additional Functionalities:
- Board ID switch for multi-card identification
- Relay output readback capability
- COS latch and interrupt control registers
- Software libraries and drivers for multiple programming environments

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### 3. Technical Specifications

Physical Characteristics:
- Dimensions: 175 mm × 107 mm (6.82” × 4.17”)
- Weight: Approx. 200 g (typical)
- I/O Connector: 68-pin SCSI-II female connector

Relay Output:
- Channels: 16
- Type: Latching SPDT (Form C)
- Isolation Voltage: 1500 V RMS
- Contact Rating:
- 125 V AC @ 0.5 A
- 30 V DC @ 1 A
- Breakdown Voltage: 1000 V RMS
- Contact Resistance: 60 mΩ max.
- Operate/Release Time: 3 ms / 3 ms
- Expected Life:
- >2×10⁵ operations @ 1 A, 30 V DC
- >1×10⁵ operations @ 0.5 A, 125 V AC
- Coil Voltage: +4.5 V nominal, 44.4 mA per relay
- Power Source: +5 V from PCI bus

Isolated Digital Input:
- Channels: 16
- Input Type: Non-polar, optically isolated
- Input Voltage Range: 0–24 V DC
- Logic Levels:
- Logic Low: 0–2 V
- Logic High: 10–24 V
- Input Resistance: 4.7 kΩ @ 0.5 W
- Isolation Voltage: 2500 V RMS (channel-to-system)
- Interrupt Sources: COS interrupt, DI channel 0 and 1
- Data Transfer: Programmed I/O

Isolated Power Supply:
- Output Voltage: +5 V
- Output Current: 170 mA max @ 40°C

Environmental Conditions:
- Operating Temperature: 0°C to 60°C (32°F to 140°F)
- Storage Temperature: -20°C to 80°C (-4°F to 176°F)
- Relative Humidity: 5% to 95%, non-condensing

Power Requirements:
| Model | +5V | +3.3V | +12V |
|--------|------|-------|------|
| PCI-7256 (typical) | 340 mA | — | — |
| PCI-7256 (max, all relays active) | 980 mA | — | — |
| PCIe-7256 (typical) | — | 36.3 mA | 141 mA |
| PCIe-7256 (max, all relays active) | — | 38.2 mA | 464 mA |

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### 4. Functionality

The PCI-7256 operates as a digital I/O interface card for industrial control systems. It provides relay-based output control and isolated digital input monitoring through a single 68-pin SCSI-II connector.

Operation Principles:
- Latching Relay Outputs:
Each relay uses a dual-coil latching mechanism. The relay maintains its last state (SET or RESET) even when power is removed, ensuring output persistence during power failures. The relays are controlled via software registers or library functions, and their status can be read back for verification.

- Isolated Digital Inputs:
Each input channel is optically isolated using PC-3H4 photo-couplers, providing noise immunity and protection from voltage transients. Inputs can be configured with or without RC filtering for AC or DC signal conditioning.

- Interrupt Handling:
The card supports two interrupt modes:
1. Change-of-State (COS) Interrupt: Triggered when any enabled input changes state.
2. Dedicated Channel Interrupts: Triggered by rising edges on DI channel 0 and/or 1.

Applications:
- Industrial ON/OFF control
- External high-power relay driving and signal switching
- Laboratory and process automation
- Limit switch and contact status monitoring
- Integration with A/D and D/A cards for complete data acquisition systems

Compatibility:
- PCI-7256: Standard 32-bit PCI bus
- PCIe-7256: PCI Express x1 slot
- Supported OS: Windows 95/98/NT/2000 and later (via PCIS-DASK drivers)
- Supported Software: LabVIEW®, HP-VEE, ISaGRAF™, InTouch™, InControl™, OPC Server

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### 5. Components & Accessories

Included Items:
- PCI-7256 or PCIe-7256 card
- ADLINK Software CD (drivers, libraries, manuals)
- Software Installation Guide
- User’s Manual

Optional Accessories:
- DIN-68S-01: Terminal board with one 68-pin SCSI-II connector and DIN-rail mounting
- ACL-10569-1: 68-pin SCSI-II cable (1 meter, AMP-787082-7 compatible)

Connectors:
- 68-pin SCSI-II female connector (CN1)
- Provides access to all DI and relay channels
- Supports external LED connections for relay status indication

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### 6. Installation & Setup

Installation Steps:
1. Power off the PC and install the PCI-7256 into an available PCI slot (or PCIe-7256 into a PCIe x1 slot).
2. Secure the card and connect the 68-pin SCSI cable to the terminal board if required.
3. Install the ADLINK software drivers from the provided CD.
4. Configure the Board ID using DIP switch S1 (values 0–15) for multi-card systems.
5. Optionally configure input filtering via jumpers JP1 (DI0–DI7) and JP2 (DI8–DI15) for AC or DC input modes.
6. Connect external LEDs to JP3/JP4 if remote relay status indication is desired.

Precautions:
- Handle the card using anti-static precautions.
- Do not apply power if physical damage is observed.
- Ensure correct LED polarity and voltage (<3V forward voltage).

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### 7. Performance & Capabilities

Relay Performance:
- Fast switching: 3 ms operate/release time
- High endurance: >200,000 operations at rated load
- Maintains state during power loss (latching design)
- Supports both AC and DC loads

Digital Input Performance:
- High isolation (2500 V RMS) for industrial environments
- Non-polar input design simplifies wiring
- Optional RC filtering for noise suppression
- COS detection with 8.25 MHz sampling (minimum pulse width 122 ns)

Efficiency:
- Power-saving latching relays reduce continuous current draw
- Onboard isolated +5V supply supports dry contact inputs up to 170 mA

Limitations:
- Relay contact ratings limited to 0.5 A @ 125 V AC or 1 A @ 30 V DC
- COS detection limited by input pulse width and sampling rate
- Only one interrupt mode (COS or channel-based) can be active at a time

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### 8. Standards & Compliance

- Bus Standards: PCI Local Bus Specification Rev. 2.2 / PCI Express Base Specification
- Electrical Isolation: 1500 V RMS (relay), 2500 V RMS (input-to-system)
- Safety & EMC: Designed for industrial environments with optical isolation and noise immunity
- Software Standards:
- PCIS-DASK driver library for Windows
- OPC, DDE, and ActiveX support for SCADA/HMI integration
- LabVIEW® and HP-VEE driver compatibility
- Environmental Compliance: RoHS-compliant manufacturing (per ADLINK standard)

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### 9. Additional Information

Warranty:
- 1-year limited warranty against defects in materials and workmanship
- Warranty void if product is modified, misused, or serial number removed
- Out-of-warranty repairs available (parts and labor charged)

Support & Service:
- Technical Support: nudaq@adlink.com.tw
- Sales & Service: service@adlink.com.tw
- Website: [www.adlinktech.com](http://www.adlinktech.com)
- Phone: +886-2-82265877
- Fax: +886-2-82265717
- Address: 9F, No. 166, Jian Yi Road, Chungho City, Taipei 235, Taiwan

Maintenance:
- Periodically inspect connectors and relays for wear or contamination
- Use proper contact protection circuits (RC, diode, zener, or varistor) for inductive loads
- Store in dry, static-free environment when not in use

Software & Updates:
- Drivers and libraries provided on ADLINK CD
- Updates and documentation available online
- Supported programming environments: C/C++, Visual Basic, LabVIEW®, HP-VEE, ISaGRAF™, InTouch™, InControl™, OPC

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### Summary

The ADLINK PCI-7256 / PCIe-7256 is a robust, industrial-grade digital I/O card combining 16 latching relay outputs with 16 optically isolated digital inputs. Its latching relay design ensures output state retention during power loss, while optical isolation and COS interrupt capabilities provide reliable input monitoring in electrically noisy environments. With comprehensive software support, flexible configuration options, and proven ADLINK reliability, the PCI-7256 is ideal for automation, control, and monitoring applications requiring dependable digital interfacing and long-term operational stability.