TESTO 6681 Instruction Manual page 29

1.3.3.3 Connecting the relay outputs
Only have the transmitter wired and connected by authorized
personnel with the voltage disconnected.
There is the option of twelve terminals for a total of four relays. The
designations NC/C/NO (normally closed contact/root or pin/normally open
contact) are etched on the surface of the board.
Using M screw connection
4 Feed connection cables for the relays through opened M 20 x 1.5
screw connection (item (10) of Overview of terminals, chapter
1.3.3.1, page 26.
5 Strip cable ends and clamp on wire end ferrules.
6 Connect relays according to chosen function (NC/NO) (see
diagrams below; relay 1 is shown as an example of a connection).
Using plug-in connections (optional)
Only insert or disconnect the plug-in connection when the
voltage is disconnected.
1 Clean the connector of the probe line and the coupling of any
foreign matter.
Do not disconnect the connector of the probe line from the
instrument for extended periods to protect against
contamination.
testo 6681 Ethernet
Relay terminal strip (item (3)
of Overview of terminals,
chapter 1.3.3.1, page 26.
- 1.3 Commissioning 29