TESTO 6681 Instruction Manual page 27

The busy light (alarm/status light) only comes on when the
relay is switched (closed). Monitoring the functionality of the
alarm circuit is therefore not possible with this switching
operation.
5 Close M 20 x 1.5 screw connection (item (10) in Overview of terminals,
chapter 1.3.2.1).
1.3.2.4 Plug-in connection option
As an option, the PG screw connections of the signal and supply lines can be
replaced with plug-in connections that are installed at the housing, see Fig. 1
and 2. The relay cabling occurs via standard cable entries and PG screw
connections, see Fig. 3 and 4.
Transmitter housing
testo 6681
- 1.3 Commissioning 27