Viessmann VITOPEND 200 Installation And Service Instructions Manual page 103

Extension for external connections (accessories)
External extension H2
The external extension is connected
to the boiler control unit via the KM
BUS. The following functions can be
controlled or processed simulta-
neously via the extension:
A
Mains isolator (on site)
fÖ
Power supply
Function description
(cont.)
aVD
&
External blocking
(terminals 2 ‐ 3)
&
External demand
(terminals 1 ‐ 2)
&
External heating program
changeover (terminal 1 ‐ 2)
The allocation of the "External
heating program changeover"
function is selected via coding
address "91".
aVG KM BUS
103