ADLINK LPCIe-8124-C Encoder Card Trigger Configuration Guide

ADLINK LPCIe-8124-C Encoder Card Trigger Configuration and Debugging Guide

ADLINK LPCIe-8124-C is a high-performance four channel encoder and high-speed trigger output card based on PCIe bus, designed for industrial automation scenarios that require precise positioning and synchronous triggering, such as automatic optical inspection AOI, distance measurement, motion control feedback, etc. This card supports up to four 32-bit orthogonal encoder inputs (compatible with A/B phase, CW/CCW, OUT/DIR formats, etc.), with a maximum input frequency of 18 MHz (4x multiplier mode), and is equipped with 14 built-in 32-bit comparators, which can flexibly configure multiple position comparison trigger modes such as manual, linear, table, and timing. The trigger output frequency is up to 4.4 MHz, and it provides three output interfaces: TTL, 5-24V open collector, and differential, suitable for various actuators.

Product positioning and core application scenarios

LPCIe-8124-C plays the role of a "position synchronization trigger" in the system. It reads the position value feedback from the encoder in real time, matches it with the preset comparison point, and once it reaches the specified position, immediately generates precise trigger pulses for triggering camera capture, light source flicker, laser marking, or actuator action. Compared to solutions that rely on software polling or CPU interrupts, hardware level triggering can ensure microsecond level response certainty and is a key component of high-speed and high-precision detection equipment.

Typical applications:

AOI detection: When the stage moves to a specific coordinate, it triggers a high-resolution camera to capture PCB solder joints or components.

Distance/angle measurement: Based on the encoder pulse count, trigger sampling at equidistant positions to construct contour data.

Flying needle test: precise control of probe contact timing.

Printing/Packaging: Achieving equidistant marking or cutting on continuously moving materials.

Hardware Overview and Interface Description

2.1 Main Technical Parameters

Project specifications

Number of channels: 4 encoder inputs+4 trigger outputs

Encoder input frequency up to 18 MHz (4 × A/B phase mode)

Trigger output frequency up to 4.4 MHz

The trigger pulse width can be programmed from 0.1 μ s to 3.2765 ms

Counter bit count 32 (encoder count)

14 comparators per channel (32-bit)

FIFO 1023 points/channel (used for pre stored comparison points in table mode)

Digital I/O per channel: EA+/-, EB+/-, EZ+/-, LTC (latch input), TRG (trigger output)

Isolation characteristics: Partial I/O optical isolation, isolation voltage of 2500 VRMS

Interface 50 pin SCSI-II connector

Power supply slot+5V/900mA, external+5V/500mA (for output)

Working temperature 0~50 ° C

2.2 Definition of connector pins (50 pin SCSI-II)

Encoder signal: EAx+, EAx -; EBx+, EBx-； EZx+, EZx-（x=1~4）， Differential or single ended input.

Position latch input: LTC1~LTC4 (optically isolated, with common terminal INCOM).

Trigger outputs: TRG1~TRG4 (optically isolated collector with OUTCOM common terminal), as well as TTL-OUT1~4 and TTL-IN1~4 (non isolated TTL level).

Power supply: DGND (Digital Ground), external power input for open collector electrode output.

Pin allocation is detailed in the table on page 3 of the manual. When wiring, it is important to pay attention to the polarity of differential signals (+/- pairing) and the voltage range of isolated terminals.

Encoder input configuration and counting mode

3.1 Input Interface Type Selection

LPCIe-8124-C supports three encoder signal formats, which can be configured through software:

A/B phase (orthogonal): A standard incremental encoder that supports 1 ×, 2 ×, and 4 × harmonics (the highest frequency at 4 × is 18 MHz, which means that when the encoder itself has a frequency of 4.5 MHz, it reaches a counting resolution of 18 MHz after 4 harmonics).

CW/CCW: Forward/Reverse Pulse, suitable for certain absolute values or stepper motor drive feedback.

OUT/DIR: Pulse+direction, commonly used in servo drive outputs.

3.2 Counting and comparator mechanism

Each channel has an independent 32-bit up/down counter that tracks position in real-time.

Built in 14 32-bit comparison registers, multiple comparison positions can be set simultaneously. When the count value matches any comparison value, the hardware automatically triggers the corresponding output action.

FIFO (1023 points) is used for "table mode", where users can pre install a series of comparison positions, and the cards will be matched one by one in order, suitable for continuous triggering with equal or non-uniform intervals.

3.3 Index (EZ) Signal and Reset

The encoder index (Z-phase) can be used to reset the counter or set a preset value, achieving absolute origin reference. It can be configured to automatically reset the counter every time the Z signal arrives, or triggered through software instructions.

Trigger output mode and pulse parameters

4.1 Trigger Output Type

TTL output (TTL OUTx): Standard 5V level, suitable for connecting camera trigger inputs or high-speed counters.

Open collector electrode output (TRGx): can be connected with an external pull-up resistor up to 5-24V, driving relays, solenoid valves or PLC inputs, with optical isolation and strong anti-interference ability.