General
Serial standards	2 x RS-232/422/485, 2 x RS-422/485
Maximum baud rate	921.6 kbps
FIFO memory	128 Byte
Insulation	2 kV
Operating temperature standard	0 °C
Relative humidity	5 %
Power consumption isolated	850 mA
ADDC® technology

The Moxa CP-134U is a 4-port universal PCI serial card developed for industrial automation applications requiring PC-based data acquisition over long distances and in multi-point topologies. The card supports RS-422/485 interfaces and offers flexible configuration with two ports capable of operating in both RS-232 and RS-422/485 modes, as well as two additional ports dedicated exclusively to RS-422/485. The serial card is designed for use in systems with 3.3/5 V PCI and PCI-X buses, enabling data transfer rates of up to 921.6 kbps per port. The integrated ADDC® technology (Automatic Data Direction Control) ensures precise control of data direction during RS-485 communication, simplifying the use of complex multi-point networks. The card features a 128-byte FIFO buffer and supports both hardware- and software-based flow control (RTS/CTS, XON/XOFF), enhancing reliability at high data rates.

Applications

The CP-134U is suitable for industrial applications where multiple serial devices are connected to a PC via a shared line, for example in manufacturing automation, building automation, or process monitoring. In RS-485 mode, the card can connect up to 31 devices in a daisy-chain topology over distances of up to 1.2 km. The card is designed for use in environments with high requirements for operational safety, particularly in industrial automation, where stable and reliable data transmission is critical.

Functions and Features in Detail

The card features a DB44 connector and integrated LED indicators for transmit (Tx) and receive (Rx) at each port, visually displaying the communication status. The serial card is equipped with a MU860 communication controller compatible with the 16C550C standard. The maximum number of installable cards per PC is eight, enabling scalability for extensive applications. The card is available in two variants: the standard version CP-134U and the isolated version CP-134U-I, which includes 2 kV electrical isolation to prevent damage from voltage spikes or potential differences.

Technology Explained Simply

The ADDC® function automatically controls data direction during RS-485 communication, eliminating the need for manual control of transceiver enable signals. This simplifies programming and increases reliability, especially in multi-point networks. The 128-byte FIFO buffer reduces processor load, as more data can be transferred in a single burst without frequently triggering CPU interrupts. Support for flow control via RTS/CTS and XON/XOFF prevents data loss when the receiver is overloaded.

Compatibility and Accessories

The CP-134U is compatible with a wide range of operating systems, including Windows (from DOS to Windows 10, including embedded systems), various Linux kernel versions (2.4.x to 5.x), and UNIX systems such as QNX 6, SCO OpenServer, UnixWare 7, Solaris 10, and FreeBSD. Driver support also includes specialized real-time and embedded systems like WEPOS. The card is available for standard and wide temperature ranges, with the standard version designed for 0 to 55 °C and the wide temperature version for -40 to 85 °C. Ambient humidity is 5 to 95 % (non-condensing).

Installation and Mounting

Installation is performed by inserting the card into a free PCI slot of a PC. The card is designed as a universal PCI board, ensuring compatibility with 3.3/5 V PCI and PCI-X bus systems. Power supply is provided via the PCI bus (5 VDC), with the standard version consuming 180 mA and the isolated version consuming 850 mA. Physical dimensions are 82.5 x 120 mm (standard) and 115 x 120 mm (isolated version). The card is supplied with an M44-to-4x-DB9-M cable (50 cm), enabling connection to standard DB9 connectors.

Operational Advantages

The card offers a high data rate of up to 921.6 kbps per port and a maximum data transfer performance exceeding 700 kbps, suitable for time-critical applications. The integrated isolation (in CP-134U-I) protects systems from electrical interference. Comprehensive driver support for various operating systems facilitates integration into existing IT infrastructures. The LED indicators enable quick diagnosis of communication issues. The high MTBF (Mean Time Between Failures) of 480,209 hours underscores the card’s reliability for industrial operating conditions. The card complies with standards EN 55032/35, CISPR 32, FCC Part 15B Class B, as well as IEC 61000-4-2 and -4-3, confirming suitability for use in electromagnetically sensitive environments. The card is also RoHS, CRoHS, and WEEE compliant, ensuring environmental compatibility.

The card is supplied with an M44-to-4x-DB9-M cable (50 cm). The delivery includes a single serial board from the CP-134U series.