ADLINK cPCI-3544/3534/3538 Serial Cardcard Configuration Practice

ADLINK cPCI-3544/3534/3538 Multi Port Serial Port Module Integration and Driver Practical Guide

In industrial grade CompactPCI systems, multi serial port expansion is a common requirement for connecting PLCs, smart meters, data acquisition terminals, and modems. ADLINK's cPCI-3534 (3 x RS-232+1 x isolated RS-422/485), cPCI-3544 (4 x isolated RS-422/485), and cPCI-3538 (8 x RS-232) serial communication modules are widely used in transportation, power, military engineering, and other fields due to their 16C550 compatible controller, maximum 115.2kbps speed, and PCI plug and play features. However, the switch settings, terminal resistance matching, isolation grounding, and driver installation under different operating systems are often difficult points in engineering debugging when multiple cards coexist. This article is based on the original factory technical manual, providing a practical technical reference for on-site engineers from hardware configuration, multi card recognition, driver deployment to troubleshooting.

Product Series Overview and Selection Decision

All three modules adopt 3U cPCI specifications (160 × 100mm), 32-bit PCI 2.1 bus, and support shared IRQ and automatic allocation of I/O addresses. The difference lies in:

CPCI-3534: 3 standard RS-232 ports (complete 9-wire system, including hardware flow control) and 1 isolated RS-422/485 port (isolated voltage 2500VDC) that can be switched between software and dial-up. Suitable for scenarios where a small number of RS-232 devices are paired with a long-distance differential communication channel.

CPCI-3544: 4 fully isolated RS-422/485 ports, each channel is independently isolated (500VDC), supports RS-485 automatic direction control, and can install up to 8 cards (32 ports), making it an ideal choice for pure differential multi node bus applications.

CPCI-3538: 8 standard RS-232 ports, without onboard isolation, but can independently select isolated RS-232/422/485 for each port through an external C888XB expansion box. Suitable for high-density standard serial port connection.

Selection key: If multiple frequency converters or intelligent sensors are needed on site to form an RS-485 network, and each device is dispersed in different potential areas, cPCI-3544 is preferred; If only one isolation differential port is needed and an RS-232 debugging port is required, select cPCI-3534; If all are RS-232 and require more than 4 ports, cPCI-3538 has the highest cost-effectiveness.

Hardware interface and wiring specifications

1. Connectors and cables

CPCI-3534/3544: The front panel has a DB37 female connector, which is connected to four ports through branch cables (C425M with four DB25 male connectors, or C409M with four DB9 male connectors).

CPCI-3538: The front panel is a DB62 female head, which outputs 8 ports through C825M (8 × DB25) or C809M (8 × DB9) cables.

All cables have shielding layers, and it is recommended to ground them at one end to reduce common mode interference.

2. Key points of pin definition

RS-232 port (A/B/C of 3534, all 3538): standard TXD, RXD, RTS, CTS, DSR, DTR, DCD, RI, GND, supports hardware flow control. When connecting DTE devices (such as computers), cross connect TXD/RXD, and connect DCE devices (such as modems) with straight through lines.

Differential ports (Port D of 3534, all of 3544):

RS-422 full duplex: TXD+/- connected to each other RXD+/-, RXD+/- connected to each other TXD+/-.

RS-485 half duplex: D+is connected to D+, D - is connected to D -, and all nodes are connected to the same bus.

Each port of 3544 has an independent isolated ground (GND), which must be connected to the signal ground of external devices, but cannot be mixed with the system digital ground (GND), otherwise it will damage the isolation performance.

Terminal resistance: JP1 (RS-422) and JP2 (RS-485) of 3534 are jumper caps, and a short circuit activates the 120 Ω terminal; 3544 Each port corresponds to two sets of jumpers (such as JP1/JP2 for Port A, JP3/JP4 for Port B, etc.). Proper configuration of terminal resistors is crucial for the stability of long-distance communication, and only devices at both ends of the bus should be enabled.

Coexistence of multiple cards and card number configuration

Due to the automatic allocation of resources by the PCI bus, but the COM port number needs to be fixed, each module distinguishes the card order through hardware switches.

1. cPCI-3534/3538 (up to 2 cards)

The onboard SW1-1 (3534) or JP1 (3538) serves as the "first card/second card" selector. ON indicates that the card is the first card in the system, and OFF indicates the second card.

The first card is assigned a lower COM port number (such as COM3~COM6), while the second card is assigned a higher COM port number (such as COM7~COM10).

It is strictly prohibited to turn on or off two cards at the same time, otherwise the system cannot distinguish and may cause unknown devices or port numbers to appear in the device manager incorrectly.

2. cPCI-3544 (up to 8 cards)

Set the binary card number (0-7) using the SW1-3 three digit dip switch. The uniqueness of the card number determines the order of port enumeration.