User manual

13
Connecting relays to the Hera
The Hera must be set in ‘Argos attached’ operation mode.
Refer to the section “installer menu” for details.
The Argos must be set up as follows:
• ‘Source’ switch in ‘micro’ position;
• the setting of the THRESHOLD potentiometer is not
important because the threshold is fully controlled by the
Hera;
• ‘Speed’ switch on ‘slow’;
• ‘Noise’ switch on ‘OFF’.
• For the ‘Hold’ switch, choose the setting most appropriate
for your application (see the Argos manual for more
information).
CONNECTING RELAYS TO THE HERA
Hera has two open-collector logic outputs. The rst is for
signalling (warning output) that the sound level threshold
has been exceeded and the second usually to shuts off the
electrical power (alarm/cut-off output) if the sound level has not
been reduced after the warning.
As these outputs are open-collector outputs, they can be used
to provide control over two external relays or also be used to
drive logic systems such as Programmable Logic Controller
(PLC) in industrial environments.
Relays can be connected using the connector labelled ‘RELAY
OUTPUTS’. Only use 12V DC relays. No external power
supply is required, so do not connect any form of power to the
Hera’s relay outputs.
The different signals available at the connector are :
Pin 1 Pin 2 Pin 3 Pin 4
Ground POWER CUT relay WARNING relay +12 V dc
This numbering is arranged looking at the rear panel, from left
to right.