General
Number of ports	8
Interface standards	RS-422, RS-485
Data bits	5, 6, 7, 8
Stop bits	1, 1.5, 2
MTBF	1.147.210 Stunden (Telcordia SR332)

The CP-138U from Moxa is an 8-port serial card for industrial applications, providing RS-422/485 interfaces via a universal PCI bus. It is particularly suitable for applications requiring high port density, such as machine control, plant communication, or general industrial automation. The card is based on the MU860 controller, which is fully 16C550C-compatible, and features a 128-byte FIFO, enabling efficient data processing. The integrated Tx/Rx LEDs per port support quick diagnosis of transmit and receive activities.

Applications

The CP-138U is designed for use in industrial environments where a high number of serial interfaces are required. Typical applications include communication with sensors, control devices, machine controls, or in decentralized automation systems. The card is designed for operation in computers equipped with a 32-bit universal PCI bus, and can support up to eight cards per PC, enabling high scalability.

Features and Specifications in Detail

The card offers eight serial ports supporting both RS-422 and RS-485. The RS-485 interface can operate in both 2-wire and 4-wire modes, providing flexibility in network configuration. Data transfer rates range from 50 bps to 921.6 kbps, sufficient for many industrial communication requirements. Interface configuration includes various data bits (5, 6, 7, 8), stop bits (1, 1.5, 2), parity types (none, even, odd, Space, Mark), and flow control options (none, XON/XOFF). The serial signals include standard signals for RS-232, RS-422, and RS-485, including GND lines.

Technology Explained Simply

The use of the MU860 controller, compatible with the 16C550C standard, ensures reliable and widely supported interface control. The 128-byte FIFO buffer reduces the load on the host computer by temporarily storing data while the processor handles other tasks. Support for the universal PCI bus allows installation in various PC systems, regardless of the specific PCI revision. The operating temperature range of 0 to 55 °C makes the card suitable for use in controlled industrial environments, although not for extremely cold or hot conditions.

Compatibility and Accessories

The CP-138U supports a wide range of operating systems, including Windows (from DOS to Windows 10, including server and embedded versions), Linux (kernel 2.4.x to 5.x), and UNIX systems such as QNX 6, SCO OpenServer, UnixWare 7, Solaris 10, and FreeBSD. Software support is thus available for many industrial and embedded systems. The card is designed for use in standard PCs equipped with a PCI slot.

Installation and Mounting

Installation is performed by inserting the card into a free PCI slot of the host computer. The card features a DB62 socket to which serial devices are connected. Power is supplied via the PCI bus (5 VDC, 135 mA). Physical dimensions are 82 x 135 mm, representing a compact form factor. Installation requires no additional tools or special mounting aids, as the card is inserted directly into the PCI slot.

Operational Advantages

The high port density of eight serial interfaces on a single card reduces the number of required expansion cards and simplifies system architecture. The integrated LED indicators facilitate troubleshooting, as transmit and receive activities can be visually monitored. Support for multiple operating systems increases flexibility in system selection. Certifications to EN 55032/35, CISPR 32, FCC Part 15B Class B, as well as IEC 61000-4-2 and -4-3, ensure good electromagnetic compatibility. The MTBF of 1,147,210 hours (according to Telcordia SR332) indicates high reliability. The card is RoHS, CRoHS, and WEEE-compliant, ensuring environmental compatibility. The warranty period is five years.