Serial interface...???

Answered Question
Sep 6th, 2010
User Badges:

Hi,



I observe in serail interface have common line i.e. DCD=up  DSR=up  DTR=up  RTS=up  CTS=up?? what is mean this and use.

Correct Answer by Peter Paluch about 6 years 10 months ago

Hello Abhinay,


These are control signals (dedicated wires in the cable) used in serial interfaces that describe the state of two interconnected devices.


  • DCD - Data Carrier Detect. Commonly used with analog modems, this signal is set by a modem if a successful connection has been established with the opposite modem (a carrier wave has been detected). I am not sure if there is any sensible meaning for this signal when using serial interconnections directly between two routers.
  • DSR - Data Set Ready, DTR - Data Terminal Ready. Each of this signals is used by one end of a serial connection to announce its readiness (whether the device is activated). One end of a serial link sets the DSR and verifies the DTR, the other end does this in the opposite manner. Usually, a router is called Data Terminal while a modem is called Data Set.
  • RTS - Request To Send, CTS - Clear To Send. These two signals are used for hardware flow control to enable both devices on a serial link to announce their readiness to accept data.


You may find detailed information if you look for details on RS-232.


Best regards,

Peter

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Correct Answer
Peter Paluch Mon, 09/06/2010 - 11:34
User Badges:
  • Cisco Employee,

Hello Abhinay,


These are control signals (dedicated wires in the cable) used in serial interfaces that describe the state of two interconnected devices.


  • DCD - Data Carrier Detect. Commonly used with analog modems, this signal is set by a modem if a successful connection has been established with the opposite modem (a carrier wave has been detected). I am not sure if there is any sensible meaning for this signal when using serial interconnections directly between two routers.
  • DSR - Data Set Ready, DTR - Data Terminal Ready. Each of this signals is used by one end of a serial connection to announce its readiness (whether the device is activated). One end of a serial link sets the DSR and verifies the DTR, the other end does this in the opposite manner. Usually, a router is called Data Terminal while a modem is called Data Set.
  • RTS - Request To Send, CTS - Clear To Send. These two signals are used for hardware flow control to enable both devices on a serial link to announce their readiness to accept data.


You may find detailed information if you look for details on RS-232.


Best regards,

Peter

Actions

This Discussion