m-e Bell-556 TX Betriebs- Und Montageanleitung Seite 20

GB
Bell-556 TX
CONNECTION (POTENTIAL-FREE)
A potential-free (simple bell push) can be connected directly to the converter.
The push-button is connected to the black connection line (1 S) and one of the
two red connection lines (1 R). The second red connection line remains free
GB
and should be insulated.
To Converter
(1 R +S)
Red
Black
20
Push
Button (NO)