Check if PD exists (by detecting a 25k Ω resistor).
The power level required for classifying PD (Class 0~3, corresponding to different power levels).
Output corresponding voltage and current based on the classification results.
If the detection fails or the classification is abnormal, the port will not output power. At this time, it is necessary to check whether the network cable is intact and whether the camera supports PoE.

Hardware installation and driver configuration
1. Physical installation steps
Turn off the host power and unplug the power cord.
Insert PCIe GIE74V into x4, x8, or x16 slots (using only x4 channels) and secure with screws.
Be sure to connect the 4-pin auxiliary power supply (CN2), otherwise the total power will be limited. The CN2 pin is defined as two GND channels and two+12V channels (see Table 6 in the manual), and it is recommended to use cables of 16AWG or above.
Connect the camera cable to any RJ45 port and ensure that the cable meets Cat5e or higher standards, and all four pairs of cables are connected (PoE requires all pairs of cables).
2. Driver installation
Obtain the Intel I210 network card driver (PCIe-GIE74V using I210 chipset) from the ADLINK official website or Intel Download Center. After installation, four "Intel I210 Gigabit Network Connections" should appear in the System Device Manager, corresponding to each of the four physical ports. If the recognition is incomplete, check the PCIe slot connection or BIOS settings.
3. Multi card support
The host can install multiple PCIe-GIE74V cards, and each card needs to set a unique ID through SW1 (but the manual does not clearly list the location and setting table of SW1, please refer to the experience of the GIE7x series, default ID=15, which means all cards are turned on). Multi card systems need to pay attention to the total power load to ensure that the host power supply can provide sufficient+12V current.
Detailed explanation of connectors and status indicator lights
1. RJ45 Ethernet port
All four RJ45 ports are standard Gigabit Ethernet interfaces that support automatic negotiation of MDI/MDIX. Each port integrates two LED indicator lights:
LED1 (speed indicator): Off=10Mbps, Green=100Mbps, Yellow=1000Mbps.
LED2 (link/activity): Off=no link, green constant=link established, green flashing=data transmission and reception in progress.
2. Board size and heat dissipation
The card size is 167.6mm × 64.9mm and is a standard half height PCIe card. The working temperature is affected by PoE power: up to 55 ° C for 32W load and up to 50 ° C for 60W load. When outputting high power, it is necessary to ensure good ventilation in the chassis and install a fan if necessary.
3. Auxiliary power connector (CN2)
4-pin Molex interface (spacing 4.2mm), pin distribution:
Pin1、Pin2:GND
Pin3、Pin4:+12V
Pay attention to polarity, misconnection may damage the board.
Common troubleshooting and solutions
1. The camera cannot receive PoE power supply
Check the Ethernet cable: Ensure that all four pairs of wires are conductive for Cat5e or above (PoE requires two sets of wires, 1/2 and 3/6, and 4/5 and 7/8). Replace the test with a known good Ethernet cable.
Check power connection: Confirm that the 4-pin auxiliary power supply is correctly connected and that the host power supply can provide sufficient+12V current. If powered solely by PCIe, the total power limit is 20W, which may not be sufficient to start all ports.
Check camera type: Some older GigE cameras do not support PoE and require an external power supply.
Check protection trigger: If overcurrent or overvoltage has occurred previously, the system needs to be restarted to reset the protection status.
Check the driver: Ensure that the Intel I210 driver is installed properly and that the network card has no abnormal flags in the device manager.
2. Frame loss or lag in image transmission
Network congestion: Simultaneous transmission of four cameras may exceed the processing capacity of a gigabit network. Check if Jumbo Frame is enabled and set the MTU of the camera and capture card to 9000.
CPU load too high: Use Interrupt Modulation to reduce interrupt frequency or shrink camera image ROI to reduce data volume.
Network cable quality: Long distance or poor quality network cables can lead to high bit error rates and cause retransmission. It is recommended to use shielded Cat6 cables.
3. The system cannot recognize all four network ports
Check if the PCIe slot has a bandwidth of x4 or higher. If inserted into slot x1, only one port may be available.
Check if PCIe channel is enabled in BIOS, some motherboards need to enable 'Above 4G Decoding' to support multiple devices.
Try unplugging, reinstalling, and clearing the CMOS before trying again.
4. Overheating leads to instability
Use temperature monitoring tools (such as HWMonitor) to check the temperature of the board. If the temperature exceeds 55 ° C, it is necessary to improve the heat dissipation of the chassis.
Reduce the total power of PoE (reduce the number of connected cameras or use low-power models), or increase the external fan.
Practical configuration suggestions
Power planning: It is recommended to control the actual power consumption of each PoE camera within 13W, with a total power of 52W for the four channels, which is lower than the budget of 60W, leaving a safety margin.