For example, when SW1-3 is set to 0, 1, 2..., they correspond to different cards, and port numbers are assigned in ascending order of card number.
After setting the card number, even if the PCI slot is changed, the port number remains unchanged for easy on-site maintenance.
3. Suggestions for the installation sequence of multiple cards
In Windows NT/2000/XP, it is recommended to install the first card (ON or card number 0) first, load the driver, and then install the second card, and so on, to avoid resource conflicts. Before installation, it is necessary to ensure that the system has at least one idle IRQ for PCI PnP allocation.

Isolation and grounding strategy
Port D isolation of cPCI-3534: The voltage withstand between the isolated ground (GND) and the system ground (GND) is 2500VDC. When wiring, the reference ground of external devices must be connected to this isolated ground, not GND, otherwise the isolation will fail and the optocoupler may be damaged.
Channel isolation of cPCI-3544: Each port has an independent isolation ground, and all four ports and ports to the system are isolated (500VDC). This design allows different ports to connect devices at different ground potentials, completely eliminating ground loop interference.
RS-485 bus grounding: Although isolated, in order to ensure that the common mode voltage does not exceed the isolation range, it is recommended to connect the isolated ground on the bus to the system earth ground at a single point, providing a discharge path.
Deep Analysis of Operating System Driver Installation
1. Windows NT 4.0
Go to "Control Panel ->Network ->Add Adapter", select "Install from Disk", the paths are:
3534/3538: X: NuCOM CCPI3534 NT4 or CPCI3538 NT4
3544:X:NuCOMCPCI3544NT4
During the installation process, specify the starting COM number (default COM3), and the system will arrange the first card port starting from this number.
Multi card rule: The first card (SW1-1=ON) has consecutive port numbers, and the second card (OFF) has a port number immediately following the end of the first card.
If you have previously installed an old driver, you must uninstall it before installing the new version, otherwise there may be a blue screen due to residual drivers.
2. Windows 95/98 (plug and play)
The system automatically discovers new hardware, simply follow the wizard to specify the driver path.
Due to the inability to reverse the card sequence through resources, it is entirely dependent on the ON/OFF of SW1-1/JP1 to distinguish between the first and second cards. Therefore, it is necessary to set the first card to ON and the second card to OFF.
After installation, the system will automatically add COM ports without the need for a restart (in some cases).
3. Windows 2000/XP (preferred for stability)
After plug and play hardware discovery, specify the driver directory:
3534/3538:X:SerialCommcPCI-353XWin2000-XP
3544:X:SerialCommcPCI-3544W2000
Similarly, the jumpers 3534/3538 determine the first/second card, while 3544 determines the enumeration order through the SW1-3 card number. This mechanism ensures the certainty of port numbers, which is particularly important for industrial software.
4. Linux environment
3534/3538:
Extract alnxsrc. Z, create a floppy disk image using dd, and extract tar to/etc/rayon.
Execution /Install, Select the card type according to the menu.
Ensure that the kernel source code path is/usr/src/Linux, otherwise compilation will fail.
3544:
Extract pci3544.tgz and enter the drivers directory.
Execute the installation script /3544-in. pl cards N (N is the actual number of cards), can specify TTY master device number and Callout master device number (default 70/71).
The script automatically detects 3544 devices on the PCI bus and creates device nodes (/dev/ttySx and/dev/cuix), after which standard serial port APIs can be used for programming.
5. RS-422/485 mode settings for cPCI-3544 (Windows)
3534/3538 does not require configuration, but 3544 requires selecting RS-422 or RS-485 mode for each port through the included AdlComSet.exe tool. When RS-422 is selected, the RS-485 function of the corresponding port is automatically disabled; When RS-485 is selected, automatic direction control (hardware automatic switching of transmission and reception) is automatically enabled without software intervention in RTS.
Common troubleshooting and countermeasures
Possible causes and solutions for the fault phenomenon
The system cannot recognize the poor contact of the cPCI slot on the new card or insufficient power supply on the backplane. Re plug and unplug, check the power supply of the chassis; Replace slot position
Multiple card switch status conflicts (3534/3538) or card numbers are duplicated (3544) in the device manager. Check all cards' SW1-1/JP1 to ensure one is ON and one is OFF; 3544 Check if the SW1-3 card number is unique
Serial port sending is normal, but receiving garbled baud rate/parity does not match; Terminal resistor configuration error check communication parameters at both ends; Check if the RS-422/485 terminal jumper is enabled as needed
RS-485 can only send but cannot receive direction control is not effective (3534 requires software control of RTS) 3534 needs to correctly raise/lower RTS in the program; 3544 confirms that it has been set to RS-485 mode (automatic control)