Browser controlled Channel change-over switch for RS232 DCE devices.

CSD-103 Browser controlled Channel change-over switch for RS232 DCE devices.


The MuLogic CSD-103 is an RS-232 channel change-over switch which allows one serial data port be connected to two serial redundant data channels, one as primary and the other as backup.

The unit supports both manual and automatic switching.
Automatic switching is triggered by one or more status criteria of the switched ports.
Manual switching can be done by means of a pushbutton on the unit or via an IP network by means of a Web browser. Configuration and monitoring are also done via Web browser.
The CSD-103 is connected to the network with a 10/100baseT Auto-MDI/MDIX Ethernet port.

In addition, the CSD-103 is equipped with power relays that can be used to control the power of each individual attached DCE (modem) device.
The unit can be powered from any 9 to 36 Volts or 18 to 60 Volts power source.


  • Manual and Automatic back-up control.
  • Remote monitoring and control by means of Web browser.
  • Monitored signals: RxD, CTS, DSR and DCD.
  • Supports both full duplex and half-duplex DCEs.
  • Internal power control relays.
  • 10/100baseT, Auto-MDI/MDIX Ethernet port.
  • Configuration via Web browser.
  • Isolated supply voltage input (ac and dc) for industrial applications.
  • Supply voltage: 9 to 36Vdc (10 to 26Vac) or 20 to 60V
  • dc (20 to 42Vac).Din-Rail or panel mounting.
  • Extended temperature range.

Technical Specifications

Ethernet port

  • 10/100baseT
  • Half and Full duplex
  • Auto-MDI/MDIX

Serial ports

  • Common port: DB9 female
  • DCE ports: DB9 male
  • Supported signals: TxD, RxD, RTS, CTS, DSR, DTR, DCD.
  • Monitored signals (each port): RxD, CTS, DSR, DCD.
  • Automatic back-up action configurable for each signal.

Remote monitoring and control

  • Displayed signals on Web browser: TxD, RxD, RTS, CTS, DSR, DTR, DCD.
  • Displayed signals on unit: TxD, RxD, RTS, CTS, DCD.
  • Displayed status: connected to port A or Port B
  • Power relay control (on/off or cycle): independent for port A and port B.

Power control relays

  • Contacts “normally closed”
  • Contacts Isolated from circuit: isolation voltage 1000Vrms
  • Maximum switching current 2A
  • Maximum switching voltage: 220Vdc/250Vac
  • Maximum switching capacity: 60W, 125VA
  • Electrical endurance (60W): typ. 10.000 operations.

Power supply input

  • Isolated from circuit: isolation voltage 1600Vdc
  • 20-60 Vdc/20-42Vac, 3.4W max. (CSD-103/Vr2)

Dimensions and weight

  • Dimensions CSD-103: 95x145x30mm LxWxD,  Weight: 300 gr.


  • Operating temperature range: -25°C..+60°C, Humidity:5..95%
  • Storage temperature range: -40°C..+80°C, Humidity:5..95%


  • CE directives: 2004/108/EC and 2006/95/EC.
  • EMC: EN 55022, EN55024: Emission limits and immunity for residential environments.
  • EMC: EN 61000-6-2: Immunity for industrial environments.
  • Safety: EN 60950.