General
Number of ports	4
Maximum baud rate	921,6 kbps
FIFO buffer	64 Bytes
Data bits	5, 6, 7, 8
Stop bits	1, 1.5, 2

The Moxa CA-134I-T is a 4-port RS-422/485 module in PC/104 format, specifically developed for industrial applications with high requirements for data security and electromagnetic compatibility (EMC). The module provides stable serial communication in harsh environments through optical isolation of 2 kV, effectively blocking interference and voltage spikes. It is designed for use in systems with limited space requirements, such as compact industrial PCs or embedded controls, and supports a maximum baud rate of 921.6 kbps, including non-standard transmission rates. Integrated status LEDs for transmit (Tx) and receive (Rx) per port enable quick visual diagnosis of communication status.

Applications

The module is suitable for use in various industrial sectors, including power plants, transportation, machine control, and remote monitoring systems. Its robust construction and support for wide-temperature operation (–40 to 85 °C) make it particularly suitable for outdoor applications or industrial environments with extreme temperatures. Compatibility with various operating systems, including Windows CE 5.0/6.0, Windows XP Embedded, Linux (kernel 2.4/2.6), and UNIX systems such as FreeBSD, QNX, and SCO, expands its application possibilities in heterogeneous IT infrastructures.

Functions and Features in Detail

The CA-134I-T features four serial interfaces supporting both RS-422 and RS-485 (in 2-wire and 4-wire configuration). Data transmission can be configured with various parameters: data bits (5, 6, 7, 8), stop bits (1, 1.5, 2), parity (None, Even, Odd, Space, Mark), and flow control (XON/XOFF or none). A FIFO buffer with 64 bytes ensures efficient data processing. The integrated software flow control enables dynamic control of data flow to avoid overruns. Configuration is performed via DIP switches, which set the I/O base address, interrupt vector, and interface type.

Technology Explained Simply

The optical isolation of 2 kV protects the module and the connected system from electrical disturbances caused by voltage spikes or differing ground potentials. This is especially important in industrial environments with strong electromagnetic fields. PC/104 compatibility means the module connects to the system via a 40-pin box header and can be integrated into a stack with other PC/104 modules. The maximum of eight modules per PC allows flexible expansion of serial interfaces. IRQs (Interrupt Requests) are limited to channels 3–7, 9–12, and 15 (shared), facilitating system integration into existing hardware environments.

Compatibility and Accessories

These cables facilitate connection to standard serial devices and enable flexible integration into existing systems.

Installation and Mounting

Installation is performed by mechanical mounting into a PC/104 system, connecting the module via the 40-pin box header. Interface configuration is done via DIP switches, which set the I/O base address, interrupt vector, and interface type (e.g., RS-422 or RS-485). The integrated LEDs allow visual monitoring of communication activity during operation. The maximum of eight modules per PC enables scalable expansion of serial interface capacity.

Operational Advantages

The combination of high isolation performance, wide temperature stability, and support for multiple operating systems makes the CA-134I-T a reliable solution for demanding industrial applications. The integrated diagnostic LEDs reduce troubleshooting time, while flexible configuration and support for non-standard baud rates enable adaptation to specific requirements. Compatibility with the PC/104 standard ensures easy integration into existing system architectures.