The CP-134U Series uses Universal PCI (3.3 V/5 V, PCI/PCI-X), suitable for legacy and industrial platforms.
The CP-134EL-A-I Series features PCI Express 1.0 (x1 interface), perfect for modern systems.

Number of Ports and Signal Types:

Both provide 4 serial ports with RS-422/485 support.

• CP-134U additionally supports RS-232 on ports 1 and 2, allowing compatibility with a wider range of devices.
• CP-134EL-A-I is dedicated to RS-422/485 only, optimized for robust industrial setups.

Isolation and Protection:

Both include 2 kV electrical isolation.
The CP-134EL-A-I also offers 4 kV surge protection, enhancing resilience against electrical spikes.

Data Rate and FIFO:

Both series support up to 921.6 kbps and feature 128-byte FIFO with software flow control (XON/XOFF).
The CP-134U additionally supports hardware flow control (RTS/CTS).

Special Features:

• CP-134U includes Moxa’s Turbo Serial Engine™ with ADDC® for automatic RS-485 direction control – ideal for multidrop networks.
• CP-134EL-A-I features Intelligent RS-485, with automatic topology analysis and troubleshooting (One-Click Installation & Troubleshooting).

Temperature Range:

• Wide-temp models are available for both, supporting -40 to 85 °C.

Dimensions and Form Factor:

• CP-134U: Larger footprint (up to 115 × 120 mm), standard PCI card.
• CP-134EL-A-I: Compact low-profile PCIe card (67.21 × 103 mm), fitting modern embedded PCs.

Software Support:

Drivers available for:

• Windows (CE, XP Embedded to Windows 10/Server 2022)
• Linux (Kernel 2.4–5.x)
• UNIX (QNX, SCO, UnixWare, Solaris, FreeBSD)

Power Consumption:

• CP-134U-I: 850 mA @ 5 V
• CP-134EL-A-I: 3,414 mA @ 3.3 V

MTBF:

• CP-134U-I: 480,209 hrs
• CP-134EL-A-I: 433,077 hrs

Conclusion:

Choose the CP-134U Series if you need PCI/PCI-X compatibility and RS-232 support.
Opt for the CP-134EL-A-I Series if you need high protection, advanced RS-485 diagnostics, and a compact PCIe form factor.