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a/b Switching Module

Switching module for door bell, door opener and light system control via 2-wire analogue line, for TFS-Dialog 200/300/400 and TFS-Universal plus


LanguagesCurrent version
Instructions a/b Switching Module V03 10/2020 PDF
CE-Declaration V03 11/2020 PDF

Instructions a/b Switching Module

Safety information

Note about qualified electrician complemented.

Note about door bell transformer complemented. Note about inflammable materials deleted.

Technical Data

Operating voltage: Values changed

Contact load capacity: Values changed

Several editiorial changes



  • 2011/65/EU with amendment 2015/863/EU replaces 2011/65/EC


  • EN 62368-1:2014+A11:2017 replaces EN 62368-1+AC:2015
  • EN 55024:2010 replaces EN 55024:2010+A1:2015
  • EN 63000:2018 new added


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The COMpact 3000 analog/ISDN/VoIP PBXs don't feature an interface for FTZ-standard doorphones.

However, you can use analog doorphones such as our TFS-Dialog 20x/30x/universal plus. In addition, you can use the TSA - a / b use this converter can convert different doorphone to a / b port .