RS-449 (EIA-449 - ISO 4902) Secondary Serial

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Image:connector_dsub9m.png 9 pin D-SUB male connector at the computer.

RS-449 is also know as: EIA-449, ISO 4902. Secondary (auxilary) channel.

Pin Name RS232 V.24 Dir Description
1 n/a 101 - Shield
2 SSR SRR 122 IN Secondary Receiver Ready
3 SSD SSD 118 OUT Secondary Send Data
4 SRD SRD 119 IN Secondary Receive Data
5 SG SG 102 - Signal Ground
6 RC RC 102b - Receive Common
7 SRS SRS 120 OUT Secondary Request To Send
8 SCS SCS 121 IN Secondary Clear To Send
9 SC SC 102a - Send Common


  • Direction is DTE (Computer) relative DCE (Modem).
  • RS232 column is RS232 circuit name.
  • V.24 column is ITU-TSS V.24 circuit name.


Category:Serial Connectors


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