RAD SRM-31S Miniature Multirate 2-Wire Modems 

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RAD SRM-31S Miniature Multirate 2-Wire Modems 


  • SRM-31S is a Synchronous Short Range Modem that operates full duplex over 2-wire unconditioned lines (twisted pair) at selectable rates from 1.2 kbps up to 128 kbps.
  • SRM-31S uses I-DSL technology and 2B1Q line-coding. It provides an operating range of up to 8 km, independent of the data rate. An adaptive equalizer provides noise immunity and high performance over mixed gauge or multi-pair cables. The modem can pass two control signals end-to-end with no interference with data transmission.
  • SRM-31S is a miniature version of ASM-31. External switches on the bottom of the unit enable easy configuration of the product. Five LED indicators show the status of the unit. The modem requires an external power source via an AC adapter (see Ordering).
  • SRM-31S can operate opposite ASM-31, ASMi-31, and the HS-U module of Megaplex-2000 and Megaplex-2100. The modem can be configured remotely, and diagnostics can be activated from the other end.
  • SRM-31S features diagnostic capabilities that include implementation of local and remote loopbacks.



  • Synchronous
  • 2-wire full duplex
  • Transmission range up to 8 km
  • I-DSL technology and 2B1Q line coding
  • Operates opposite ASM-31, ASMi-31, and the HS-U module of MP-2000 and MP-2100
  • V.24/RS.232 or V.35 digital interfaces
  • Diagnostic loops according to ITU V.54
  • Selectable data rates:
    1.2 kbps - 128 kbps
  • Configuration download option when working opposite ASMi-31
  • LED indicators

2-wire Short Range Sync Modem

+ Specify power supply: (Default is with no power supply)
115 for 115 VAC
230 for 230 VAC
* Specify digital interface:
V24 for V.24/RS-232
V35 for V.35




RAD Products

For discount pricing on RAD Data Communications  
email us at sales@data-connect.com
or call 301-924-7400