Comprehensive Product Summary – ADLINK ACL‑7124 24‑bit Digital I/O Card

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### 1. Product Overview

Product Name: ACL‑7124
Model: ACL‑7124
Series: NuDAQ® ISA Digital I/O Series
Article Number: 91‑11005‑001
Manufacturer: ADLINK Technology Inc.
Manufacturer Address: 9F, No.166 Jian Yi Road, Chungho City, Taipei 235, Taiwan, R.O.C.
Telephone: +886‑2‑8226‑5877
Fax: +886‑2‑8226‑5717 / +886‑2‑8226‑5729 (Sales)
Website: [www.adlinktech.com](http://www.adlinktech.com)

Product Type: 24‑bit Parallel Digital Input/Output (DIO) Card
Bus Interface: PC/XT ISA Bus
Compatibility: Fully hardware and software compatible with Advantech PCL‑724
EOL Status: End‑of‑Life (EOL) announced September 25, 2002 (EOL No. 20020925‑001)
Suggested Replacements:
- ACL‑7124B (Part No. 91‑11005‑101)
- PET‑48DIO (Part No. 91‑11016‑001)

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### 2. Key Features

- 24‑Channel Digital I/O: Provides 24 TTL/DTL‑compatible digital input/output lines organized as three 8‑bit ports (Port A, Port B, Port C).
- 8255 Mode 0 Emulation: Fully emulates one Intel 8255 Programmable Peripheral Interface (PPI) in Mode 0, offering flexible digital I/O control.
- Buffered Circuit Design: Incorporates buffering for higher current drive capability and improved signal integrity.
- Interrupt Support: Programmable interrupt handling via PC0 and PC4 lines of Port C, with selectable IRQ levels (IRQ2–IRQ7) and edge‑trigger configuration (rising/falling).
- Output Status Readback: Allows reading back the output latch status for verification and diagnostics.
- OPTO‑22 Compatibility: Directly interfaces with OPTO‑22 compatible I/O modules and racks (8, 16, or 24 channels).
- Software Compatibility: Supports simple 8‑bit I/O port programming (inport/outport) and ADLINK’s ACLS‑DLL1 driver for high‑level C or Windows applications.
- Hardware Compatibility: Drop‑in replacement for Advantech PCL‑724, ensuring seamless integration in legacy systems.
- Compact Form Factor: 108 mm × 107 mm PCB suitable for standard ISA slots.
- Industrial Reliability: Designed for industrial monitoring, control, and data acquisition applications.

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### 3. Technical Specifications

| Parameter | Specification |
|----------------|-------------------|
| Digital I/O Channels | 24 (3 × 8‑bit ports: PA, PB, PC) |
| Logic Compatibility | TTL/DTL |
| Input Voltage Levels | Logic High: 2.0–5.25 V; Logic Low: 0.0–0.8 V |
| Input Current | High: 20 µA; Low: –0.2 mA |
| Output Voltage Levels | Logic High ≥ 2.4 V; Logic Low ≤ 0.5 V |
| Output Current | High: –15 mA; Low: 24 mA |
| Bus Interface | PC/XT ISA Bus |
| I/O Port Address Range | 4 bytes (Hex 200–3FF) |
| IRQ Levels | Selectable IRQ2–IRQ7 |
| Power Consumption | 0.5 A @ +5 VDC (typical); 0.8 A @ +5 VDC (maximum) |
| Transfer Rate | 300 KB/s (typical); 500 KB/s (maximum) |
| Operating Temperature | 0°C to +60°C |
| Storage Temperature | –20°C to +80°C |
| Humidity | 5%–95% RH, non‑condensing |
| Dimensions | 108 mm × 107 mm |
| Connectors | 1 × 50‑pin male ribbon connector (CN1); 2 × 20‑pin headers (CN2, CN3) |
| Mounting | Standard ISA slot |
| PCB Revision | Rev. A2 (as referenced in layout diagrams) |

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### 4. Functionality

The ACL‑7124 functions as a parallel digital I/O interface card for IBM PC/XT/AT and compatible systems. It provides 24 programmable digital lines that can be configured as inputs or outputs in any combination through software control words. The card emulates the Intel 8255 PPI in Mode 0, offering three 8‑bit ports (A, B, and C). Port C can be split into two 4‑bit sub‑ports (PC upper and PC lower) for finer control.

Operation Principle:
- Each port can be independently configured for input or output.
- Outputs are latched; inputs are direct (non‑latched).
- Control words define the I/O direction and mode.
- Interrupts can be generated via PC0 (trigger) and controlled via PC4 (enable/disable).
- Supports both rising and falling edge triggers.

Typical Use Cases:
- Industrial process monitoring and control.
- Digital signal acquisition and control systems.
- Contact closure and switch/keyboard monitoring.
- Interfacing with OPTO‑22 compatible relay or sensor modules.
- Integration with A/D and D/A cards for hybrid data acquisition systems.

Compatibility:
- Hardware/software compatible with Advantech PCL‑724.
- Works with ADLINK’s ACLD‑782 (digital opto‑isolated input board) and ACLD‑785 (digital relay output board).
- Supports DOS and Windows environments via ADLINK’s NuDAQ software libraries.

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### 5. Components & Accessories

Included Items:
- ACL‑7124 24‑bit Digital I/O Card
- ADLINK CD containing NuDAQ ISA software libraries and utilities
- User’s Manual (Rev. 2.22, April 15, 2000)

Connectors:
- CN1 (50‑pin male ribbon connector): Main I/O interface for all 24 digital lines.
- CN2 (20‑pin header): Port A and Port B breakout (for daughter boards).
- CN3 (20‑pin header): Port C breakout (for daughter boards).

Connector Pin Assignments:
- CN1: 24 I/O lines (PA0–PA7, PB0–PB7, PC0–PC7) plus +5V and GND pins.
- CN2: Port A and B lines with power and ground.
- CN3: Port C lines with power and ground.

Optional Accessories:
- ACLD‑782: 16‑bit digital opto‑isolated input board.
- ACLD‑785: 16‑bit digital relay output board.
- OPTO‑22 compatible modules: For isolated I/O expansion.

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### 6. Installation & Setup

Pre‑Installation Precautions:
- Handle the card on a grounded anti‑static mat.
- Wear an anti‑static wrist strap connected to the same ground.
- Inspect for shipping damage before installation.

Installation Steps:
1. Power off the PC and remove the cover.
2. Insert the ACL‑7124 into an available ISA slot.
3. Secure the card with the mounting screw.
4. Connect external devices via the 50‑pin or 20‑pin connectors.
5. Configure base address and interrupt settings as required.

Base Address Configuration:
- Set via DIP switch SW1 (A8–A2 correspond to address lines).
- Default base address: 0x2C0–0x2C3.
- Valid range: 0x200–0x3FF (4 consecutive I/O addresses).

Interrupt Configuration:
- IRQ Level: Selectable via jumper J1 (IRQ2–IRQ7). Default: IRQ2.
- Interrupt Mode (J2):
- DIS: Interrupt disabled (default).
- EN: Interrupt always enabled.
- PGM: Programmable interrupt (enabled when PC4 = LOW).
- Trigger Edge (J3):
- Rising edge (default) or falling edge selectable.

Software Installation:
1. Insert ADLINK CD into the CD‑ROM drive.
2. Navigate to `\NuDAQISA\7124` directory.
3. Run `SETUP` to install the DOS library and utilities.
4. Files are installed to `C:\ADLINK\7124\DOS`.

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### 7. Performance & Capabilities

- Data Transfer Rate: Up to 500 KB/s (maximum), 300 KB/s typical.
- Signal Drive Capability: Up to 24 mA per output channel.
- Interrupt Handling: Supports hardware interrupts via PC0; programmable enable via PC4.
- Response Time: Determined by ISA bus latency and software polling/interrupt routines.
- Reliability: Buffered outputs and TTL/DTL compatibility ensure stable operation in industrial environments.
- Limitations:
- Inputs are not latched (no first‑event capture).
- No onboard isolation; external modules recommended for high‑voltage environments.
- ISA bus interface limits use to legacy PC architectures.

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### 8. Standards & Compliance

- Bus Standard: IBM PC/XT/AT ISA Bus (8‑bit).
- Electrical Standards: TTL/DTL logic levels.
- Environmental Compliance: Designed for industrial temperature and humidity ranges.
- Safety & Quality: Manufactured under ADLINK’s quality assurance system.
- Trademark Notice: NuDAQ® and ACL‑7124 are registered trademarks of ADLINK Technology Inc.
- Regulatory Compliance: Conforms to general industrial electronic equipment standards applicable at time of manufacture (pre‑RoHS era).

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### 9. Additional Information

Warranty:
- Coverage: One‑year limited warranty from date of purchase.
- Scope: Free from defects in materials and workmanship under normal use.
- Exclusions:
- Damage from misuse, modification, or operation beyond specifications.
- Units with removed or altered serial numbers.
- Repairs performed outside ADLINK facilities.
- Remedy: Repair or replacement at ADLINK’s discretion.
- Return Policy: Products must be securely packaged, postage prepaid, and insured.

Support & Service:
- Customer Service Email: service@adlink.com.tw
- Technical Support:
- NuDAQ: nudaq@adlink.com.tw
- NuDAM: nudam@adlink.com.tw
- NuIPC: nuipc@adlink.com.tw
- NuPRO: nupro@adlink.com.tw
- Software: sw@adlink.com.tw
- AMB: amb@adlink.com.tw
- Phone: +886‑2‑8226‑5877
- Fax: +886‑2‑8226‑5717

Maintenance:
- Keep connectors clean and free of dust.
- Avoid exposure to excessive humidity or vibration.
- Verify jumper and DIP switch settings after long‑term storage.

Product Lifecycle:
- EOL Publication Date: September 25, 2002.
- Reason for EOL: Material obsolescence and market phase‑out.
- Replacement Models: ACL‑7124B and PET‑48DIO.
- Remaining Stock at EOL: 57 units available at time of notice.

Documentation:
- User’s Guide: NuDAQ ACL‑7124 User’s Manual, Rev. 2.22 (April 15, 2000).
- Programming Support: Example C programs for initialization, I/O operations, and interrupt handling provided in manual.
- Software Tools: DOS library and utilities for direct port access and configuration.

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### Summary

The ADLINK ACL‑7124 is a robust, ISA‑bus‑based 24‑bit digital I/O card designed for industrial control and data acquisition applications. Emulating the Intel 8255 PPI in Mode 0, it provides flexible, programmable digital input and output capabilities with interrupt support and high current drive. Its compatibility with OPTO‑22 modules and Advantech PCL‑724 makes it ideal for legacy system integration and industrial automation tasks.

Although now discontinued, the ACL‑7124 remains a reference design for reliable, low‑latency digital I/O interfacing in PC‑based control systems. Replacement models such as the ACL‑7124B and PET‑48DIO continue ADLINK’s tradition of providing high‑performance, industrial‑grade data acquisition solutions.