Comprehensive Product Summary: ADLINK PCI-7251 Extension Panel

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### 1. Product Overview

Product Name: PCI-7251
Model: PCI-7251
Series: PCI-725X Series (includes PCI-7250, PCI-7251, LPCI-7250, LPCIe-7250, cPCI-7252)
Article Number: PCI-7251
Manufacturer: ADLINK Technology Inc.
Product Type: 8-Channel Relay Output and 8-Channel Isolated Digital Input Extension Card for PCI-7250
Form Factor: Standard PCI extension module
Manufacturer Website: [www.adlinktech.com](http://www.adlinktech.com)

The ADLINK PCI-7251 is an expansion module designed to extend the I/O capabilities of the ADLINK PCI-7250 digital I/O card. It provides an additional 8 relay output channels and 8 optically isolated digital input channels, effectively doubling the I/O capacity of the base card. Up to three PCI-7251 modules can be connected to a single PCI-7250, allowing a total of 32 relay outputs and 32 isolated digital inputs.

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### 2. Key Features

- Expansion Capability: Adds 8 relay outputs and 8 isolated digital inputs to the PCI-7250 main card.
- Scalability: Supports up to three PCI-7251 modules per PCI-7250, expanding total I/O to 32 relay outputs and 32 isolated inputs.
- Relay Configuration: 4 SPDT (Form C) and 4 SPST (Form A) relays, non-latching type.
- Optical Isolation: 8 optically isolated digital input channels for noise immunity and signal integrity.
- LED Indicators: Onboard LEDs display the status of each relay output for easy monitoring.
- High Isolation Voltage: 5000 VRMS isolation between input channels and system ground.
- Programmable I/O: Supports programmed I/O data transfer for flexible control.
- Compact Design: PCB dimensions of 141 mm x 102 mm, suitable for industrial and laboratory environments.
- Compatibility: Designed to operate seamlessly with the PCI-7250 main card; controlled via the PCI-7250 bus interface.
- Durability: Relay life expectancy exceeds 500,000 operations at 1 A, 24 VDC.
- Environmental Robustness: Operates in 0–60°C temperature range with 5–95% non-condensing humidity.
- Software Support: Compatible with ADLINK’s DAQPilot, PCIS-DASK, and DAQ-MTLB drivers for Windows and Linux.

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### 3. Technical Specifications

Physical Characteristics
- Dimensions: 141 mm (L) × 102 mm (W)
- Weight: Approx. 200 g (typical)
- Connector Type: 37-pin D-sub female connector
- Mounting: Standard PCI slot extension panel

Electrical Characteristics
- Power Supply: +5 VDC @ 125 mA typical
- Bus Interface: Controlled via PCI-7250 main card (no independent PCI interface)

Relay Output Specifications
- Number of Channels: 8
- Relay Type:
- Channels 0–3: SPDT (Form C, normally open)
- Channels 4–7: SPST (Form A, normally open)
- Contact Ratings:
- AC: 120 V @ 0.5 A
- DC: 24 V @ 1 A
- Breakdown Voltage: 1000 VRMS
- Contact Resistance: 100 mΩ max
- Operate Time: 8 ms typical
- Release Time: 8 ms typical
- Expected Life:
- >5×10⁵ operations @ 1 A, 24 VDC
- >2×10⁵ operations @ 0.5 A, 120 VAC
- Relay Coil Voltage: +5 V, 33 mA per relay (total 0.264 A for all relays)
- LED Indicators: One per relay channel

Isolated Digital Input Specifications
- Number of Channels: 8
- Input Type: Optically isolated, non-polarity
- Input Voltage Range: 0–24 VDC
- Logic Levels:
- Logic High: 5–24 V
- Logic Low: 0–1.5 V
- Input Resistance: 2.2 kΩ @ 0.33 W
- Isolation Voltage: 5000 VRMS channel-to-system
- Input Current: 10 mA nominal, 60 mA max
- Photo-coupler Type: PC-814
- Filter Option: Jumper-selectable AC-filter or non-filter mode

Environmental Conditions
- Operating Temperature: 0°C to 60°C
- Storage Temperature: -20°C to 80°C
- Relative Humidity: 5% to 95%, non-condensing

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### 4. Functionality

The PCI-7251 functions as an I/O expansion module for the PCI-7250. It replicates the same I/O structure and is fully controlled by the PCI-7250’s bus interface. The PCI-7251 provides additional relay outputs and isolated digital inputs, enabling users to scale their control and monitoring systems without additional PCI slots.

Operation Principle:
- Relay Outputs: Controlled via software commands through the PCI-7250. Each relay can switch AC or DC loads, suitable for ON/OFF control of external devices.
- Isolated Inputs: Each input channel is optically isolated to protect the system from high-voltage transients and noise. Inputs can be configured for AC or DC signals using onboard jumpers.
- LED Indicators: Each relay output has a corresponding LED that illuminates when the relay is energized.

Use Cases:
- Industrial automation and process control
- Laboratory instrumentation and test systems
- Machine control and signal switching
- External relay driving and contact monitoring
- Integration with A/D and D/A cards for complete data acquisition and control systems

Compatibility:
- Fully compatible with PCI-7250 main card
- Supports up to three PCI-7251 modules per PCI-7250
- Works with ADLINK’s DAQ software and drivers under Windows and Linux

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### 5. Components & Accessories

Included Items:
- PCI-7251 extension card
- User’s manual and installation guide
- ADLINK software CD (drivers and utilities)

Optional Accessories:
- DIN-37D-01: Terminal board with 37-pin D-sub connector and DIN-rail mounting
- ACLD-9137-01: General-purpose terminal board with 37-pin D-sub male connector
- ACL-10137-1MM: 37-pin D-sub male/male cable, 1 meter length

Connectors:
- 37-pin D-sub female connector for I/O interface
- Connects to PCI-7250 via ribbon cable or backplane interconnect

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### 6. Installation & Setup

Requirements:
- One PCI-7250 main card installed in the system
- Available expansion slot or mounting space for PCI-7251
- +5 VDC power supply from PCI-7250

Installation Steps:
1. Power off the host computer and disconnect all peripherals.
2. Install the PCI-7250 main card into an available PCI slot.
3. Connect the PCI-7251 to the PCI-7250 using the provided expansion connector.
4. Secure the PCI-7251 in place using mounting screws.
5. Power on the system and install ADLINK drivers (PCIS-DASK or DAQPilot).
6. Configure input jumpers (JP1–JP8) for AC-filter or DC input mode as required.
7. Verify operation using ADLINK’s DAQMaster or DAQBench software.

Jumper Configuration:
- Each input channel (DI0–DI7) has a corresponding jumper (JP1–JP8).
- Non-AC Filter (DC input): Pins 2–3 shorted (default)
- AC Filter (AC input): Pins 1–2 shorted

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### 7. Performance & Capabilities

Relay Performance:
- Operate/Release Time: 8 ms typical
- Contact Resistance: ≤100 mΩ
- Isolation: 1000 VRMS between contacts
- Life Expectancy: >500,000 operations under rated load

Input Performance:
- Isolation: 5000 VRMS
- Input Impedance: 2.2 kΩ
- Input Voltage Range: 0–24 VDC
- Input Current: 10 mA typical

System Expansion:
- One PCI-7250 supports up to three PCI-7251 modules
- Maximum configuration: 32 relay outputs and 32 isolated inputs

Efficiency & Limitations:
- Designed for low to moderate switching loads (≤1 A @ 24 VDC)
- Not suitable for high-frequency switching or high-current inductive loads without external protection circuits
- Relay contact protection recommended for inductive loads (RC, diode, or varistor circuits)

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### 8. Standards & Compliance

Bus Interface:
- 32-bit, 5 V PCI bus (controlled via PCI-7250)

Electrical Safety & Isolation:
- 5000 VRMS isolation between input channels and system ground
- 1000 VRMS relay contact breakdown voltage

Environmental Compliance:
- Designed for industrial environments with wide temperature and humidity tolerance

Regulatory Compliance:
- CE and FCC compliant (as part of PCI-7250 system)
- RoHS compliant manufacturing

Industry Standards:
- PCI Local Bus Specification 2.2
- Opto-isolation per IEC 61010-1 standards

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### 9. Additional Information

Warranty:
- Standard ADLINK limited warranty (typically 2 years)

Support & Maintenance:
- Technical support via ADLINK global service centers
- Firmware and driver updates available from ADLINK website
- Comprehensive documentation including user manual, pin assignments, and sample code

Software & Driver Support:
- Operating Systems: Windows 2000/XP/Vista/7, Linux
- Drivers:
- PCIS-DASK (Windows)
- PCIS-DASK/X (Linux)
- DAQPilot (Windows SDK)
- Third-Party Integration:
- DAQ-MTLB for MATLAB®
- DAQ-LVIEW PnP for LabVIEW™
- PCIS-VEE for Agilent VEE™
- Development Environments: VB.NET, VC++, Delphi, C#, BCB
- Utility Software: DAQMaster (device manager), DAQBench (ActiveX control suite), DAQCreator (data acquisition software)

Maintenance Recommendations:
- Periodically inspect relay contacts for wear in high-duty applications
- Use appropriate contact protection circuits for inductive loads
- Maintain clean, static-free environment during installation and servicing

Manufacturer Contact:
ADLINK Technology Inc.
9F, No. 166, Jian Yi Road, Chungho City, Taipei 235, Taiwan
Tel: +886-2-82265877 | Fax: +886-2-82265717
Email: service@adlinktech.com
Website: [www.adlinktech.com](http://www.adlinktech.com)

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### Summary

The ADLINK PCI-7251 is a robust, industrial-grade extension module that enhances the I/O capacity of the PCI-7250 digital I/O card. With 8 relay outputs and 8 optically isolated digital inputs, it provides reliable switching and signal acquisition for automation, control, and monitoring applications. Its modular design allows scalable expansion up to 32 channels, while maintaining high isolation, durability, and compatibility with ADLINK’s software ecosystem. The PCI-7251 is ideal for engineers and system integrators seeking a flexible, noise-immune, and easily expandable digital I/O solution for PCI-based industrial systems.