CompactPCI® Serial Quad Port Isolated RS-485 Interface

Proven and reliable, RS-485 (EIA/TIA-485) stays a popular fieldbus communication interface, due to simple installation via low cost twisted pair copper cables, up to 1200m length.
The SU1-TWIST is a peripheral slot card for CompactPCI® Serial systems, based on PCI Express®. The board is equipped with four isolated front panel RS-485 ports. High speed RS-485 balanced line transceivers with internal 5kV isolation barrier provide for optimum noise and EMC immunity. The SU1-TWIST is equipped with an octal PCI Express® to UART bridge. The 950-style UARTs are compatible with many asynchronous serial applications and protocols. Four isolated EIA/TIA-485 transceivers are wired to Micro-D front panel connectors, individually configurable for full-duplex operation (4+1 wire cable) or half-duplex (2+1 wire cable), either point-to-point or multipoint applications. Another four UART channels are available via the CompactPCI® Serial backplane connector P4 for versatile rear I/O usage.

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Application Notes

General Information


  • Serial Interface with Octal UART (emulating Quad) 3x RS485 isolated via front panel DSub9 1 additional RS485 isolated as redundancy reserve LED function display
  • Serial Interface with Octal UART (emulating Quad) 4x RS485 isolated via front panel microDSub LED function display


  • PICMG® CompactPCI® Serial standard (CPCI-S.0)
  • Single size Eurocard 3U 4HP 100x160mm2
  • Suitable for CompactPCI® Serial peripheral slot (PCI Express® enabled)
  • CompactPCI® Serial backplane connector P1 for PCI Express®, single lane link
  • Option CompactPCI® Serial backplane connector P4 for rear I/O

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