DNx-CSDB-509 – 8-Port CSDB & RS-232/485 Serial Communications Interface

The DNx-CSDB-509 are 8-port serial communications interfaces for Cube/RACKtangle I/O chassis respectively. The boards offer fully isolated software-configurable CSDB (Commercial Standard Digital Bus), RS-232 or RS-485 interfaces. The board is an ideal interface to serial based avionics as well as general purpose serial I/O.



  • DNA-CSDB-509 for use with “Cube” I/O chassis
  • DNR-CSDB-509 for use with RACKtangle™ I/O chassis
  • 8 independent ports
  • Each port is software-configurable as CSDB, RS-232 or RS-422/485
  • Supports both 12.5 kbit/s and 50 kbit/s CSDB rates
  • Max speed of 256 kbit/s for RS-232 and 1Mbit/s for RS-422/485
  • Completely independent bit rate settings for every port
  • 350V isolation between ports, ports and circuitry; 15kV ESD

The DNx-CSDB-509 support both 12.5 kbaud and 50 kbaud data rates in CSDB mode as well as transfer rates up to 1 Mbaud in RS-485 mode or up to 256 kbaud in RS-232 mode. It also supports communications at 12, 12.5and 50 kbaud with better than 0.1% data rate accuracy. Baud rates based on integer divisors of 4.125 MHz or 1.8415 MHz are also supported.

The DNx-CSDB-509 are compatible with a wide variety of legacy avionics devices. The board support RS-422 point to point or network applications when used in RS-485 mode and provide 200Ω software selectable TX and/or RX termination for RS-485 communications. In RS-232 mode, the layer provides TX/RX as well as the standard RTS and CTS hardware hand shaking required by many external serial devices.

I/O Chassis
Model No.


RACKtangle ®


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