ADLINK cPCI-3720: 3U CompactPCI Low Power Pentium III CPU Module

Scenario 4: Upgrading and Replacing Old Systems

The CNC control system of a certain factory is still using industrial control computers based on ISA/PCI full-length cards, facing problems of motherboard aging and difficult maintenance. By using cPCI-372B/P72 in combination with cPCI-R3720 RTM, the original 3U cPCI chassis and backplane can be used, while retaining high-value dedicated ISA/PCI expansion cards (connected through the backplane). The software is based on Windows NT 4.0 and can be directly migrated (ADLINK provides complete driver support). This solution extends the service life of the equipment without the need for large-scale rewriting of control software.

Key points of engineering deployment

1. Memory selection and installation

Only supports PC-100 144 pin SO-DIMM 3.3V SDRAM.

Suggest using ADLINK certified memory modules. Ensure that the module is securely inserted during installation and does not exceed the height limit, otherwise components may be damaged when inserted into the chassis.

2. LAN2 front panel/rear panel selection

Set through onboard DIP switches S2 and S3:

Front panel LAN2: S2 all ON, S3 all OFF.

Rear panel LAN2: All S2 are turned off and all S3 are turned on.

Do not connect LAN2 on both the front and back panels at the same time, as this may cause network conflicts or hardware damage.

3. COM1 mode configuration (cPCI-R3720)

Select through JP1-JP4 jumper:

RS-232 (default): JP1-JP4 are all Unused.

RS-422/485/485+: Please refer to the user manual table for configuration.

In RS-485 mode, if using RS-485+mode, the corresponding jumper combination needs to be selected to enable automatic direction control.

4. Installation of 2.5-inch HDD (B series)

Only supports low profile ATA HDDs with a thickness not exceeding 9.5mm.

Use the 4 copper pillars and 44 wire IDE connector from the HDD accessory kit (P/N: 58-00023-000).

During installation, pay attention to aligning the PIN1 of the IDE connection cable and ensure that all screws and connectors are securely fixed.

5. Suggestions for the installation sequence of drivers

For Windows NT systems, it is recommended to install LAN drivers first and then install service packs.

If there is a system startup warning or exception, it is recommended to reinstall the Windows NT Service Pack and install the drivers in a different order.

Tips for troubleshooting common engineering problems

Problem phenomenon 1: The system cannot be powered on or the power LED does not light up

Key points of inspection: Confirm that cPCI-3720 is fully inserted into the chassis backplane and lock the ejection device. Check if the backplane power supply is normal (3.3V, 5V, and 12V).

Key point: The power ramp circuit of cPCI-3720 requires unconditional reset when the voltage is below 3.0V (3.3V), 4.75V (5V), and 10.0V (+12V). If the power quality is poor, it may lead to frequent resets.

Problem phenomenon 2: LAN2 cannot communicate

Key points for inspection: Confirm that DIP switches S2/S3 are set correctly (front or rear panel). Confirm if LAN2 is connected to both the front and rear panels simultaneously.

Key point: The front and rear selection of LAN2 is only controlled by hardware DIP switches and does not involve BIOS settings. If the switch is set incorrectly, the operating system cannot recognize the network port.

Problem phenomenon 3: Communication abnormality of COM1 in RS-485 mode

Key points of inspection: Confirm that the JP1-JP4 jumper settings on cPCI-R3720 match the selected RS-485 mode. Check the terminal resistance configuration of external devices.

Key point: If using RS-485+mode, confirm that the jumper configuration is the corresponding automatic direction control combination. Incorrect jumper settings will result in data direction switching failure.

Problem phenomenon 4: The system frequently resets automatically

Key inspection points: Use the Hardware Doctor Utility to check if the CPU temperature and system voltage are normal. Confirm if the watchdog timer has been accidentally enabled and correctly fed to the dog in the application.

Key point: Temporarily disable the watchdog function in BIOS for troubleshooting testing. If the reset disappears, the problem lies in the WDT configuration or the dog feeding logic of the application.