ADLINK Express HL Module Selection and Heat Dissipation Configuration Guide

Monitoring tool: SEMA controller provides real-time voltage/current monitoring, which can be read through SEMA API for dynamic power management or abnormal warning.

SEMA onboard controller - embedded intelligent management core

SEMA is a key value-added feature that distinguishes Express HL from regular COM Express modules, and its integrated resources include:

Voltage/current monitoring: Real time tracking of the core power rail to assist in locating power supply anomalies.

Power timing debugging support: Record the power on timing for easy troubleshooting of startup failures.

AT/ATX mode control: software switchable, no hardware jumper required.

Logistics and forensic information: Production batches, serial numbers, and operation logs of storage modules for asset management.

Tablet control: Provides signals such as backlight adjustment and panel switch.

Universal I2C interface: expands external sensors or EEPROM.

Fault safe BIOS (dual BIOS): Automatically switches to backup when the main BIOS is damaged, ensuring system recoverability.

Watchdog timer: prevents software deadlock, supports timeout reset or interrupt.

Fan control: Supports PWM speed regulation and dynamically adjusts the speed according to temperature.

Application Practice:

In critical task systems, it is recommended to enable watchdog and configure a reasonable timeout period (such as 30 seconds), and feed the dog at regular intervals in the application.

Under the dual BIOS mechanism, users do not need to manually intervene. After the main BIOS verification fails, it automatically boots from the backup, but it should be noted that the backup BIOS version should be consistent.

The I2C interface of SEMA can be connected to ambient temperature sensors to supplement the shortcomings of onboard temperature monitoring.

Display and PCIe expansion configuration

5.1 Three independent displays

The module provides three DDI ports (DDI1/2/3), each of which can be configured as a DisplayPort, HDMI, or DVI (with level conversion required), and additionally offers:

VGA: Analog output, supports QXGA (2048 × 1536) @ 60Hz.

LVDS: Derived from eDP (two channel) conversion, supports single/dual channel 18/24 bit, and can be directly connected to industrial LCD screens.

Suggestion for multi screen applications: Three DDIs can output simultaneously (such as two DP and one HDMI), and LVDS shares bandwidth with one of the DDIs. Please refer to the carrier design guidelines to avoid conflicts.

5.2 PCIe Channel Allocation

One PCIe x16 (Gen3): can be configured as a single x16, or two x8s, or one x8+two x4s (adjusted through BIOS).

Seven PCIe x1: six from Lane 0-5 (AB group) and one from Lane 6 (CD group).

Typical configuration:

When a dedicated graphics card or high-speed FPGA acceleration card is required, it occupies x16.

If multiple gigabit Ethernet ports, serial port cards, CAN cards, etc. are required, x1 channel can be used.

Note that Gen3 speed requires high signal integrity, and cable length and connector quality must meet the standards.

BIOS and firmware advanced settings

Express HL uses AMI EFI BIOS (8 MB SPI Flash) and supports Intel AMT 9.0 (i217LM network card only). The key settings include:

Startup sequence: UEFI and Legacy boot devices can be set separately, and it is recommended to use UEFI mode to support GPT and fast boot.

AMT configuration: When enabled, remote management (KVM, SOL) can be achieved, but additional ME firmware needs to be loaded.

TPM 1.2: Onboard Atmel AT97SC3204, can be enabled in BIOS and used for BitLocker or secure boot.

Serial port redirection: COM1/COM2 supports console redirection for easy debugging of headless systems.

Dual BIOS switching: Usually does not require manual operation, but if you need to force boot from backup, you can refer to SEMA related commands.

Attention: It is recommended to back up the current configuration (through AMI's Save/Load function) before changing BIOS settings to avoid misoperation that may cause failure to boot.

Common hardware troubleshooting and solutions

7.1 Module has no response when powered on

Check if the input voltage of the power supply is within the allowable range (12V ± 5% and 5VSB normal at ATX, only 12V at AT).

Confirm that the power switch signal (PWR_BTN #) on the carrier board has been correctly pulled down (ATX mode needs to trigger power on, AT mode is always low).

Use the SEMA power timing debugging function to observe the power on sequence of each power rail and determine if there is a short circuit or undervoltage.

7.2 Sudden restart or crash during system operation

Read SEMA voltage/current monitoring data and check if+12V drops (possibly due to insufficient power supply).

Check the CPU temperature (BIOS or SEMA reading), if it exceeds 90 ° C, it will trigger overheating protection and require enhanced heat dissipation.

Check if the watchdog has been accidentally triggered (due to the application not feeding the dog in a timely manner), and temporarily disable the watchdog for testing.

7.3 Display no output or screen blur

Confirm the display interface type and cable matching (e.g. DVI requires DVI signal, LVDS requires correct panel resolution configuration).