Relay, Overview – Perle Systems IOLAN SCS User Manual
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Channels
Relay
Overview
Relay channels can open or close a contact for a higher voltage circuit using a lower level control
voltage. The Relay output channels work as a physical on/off switch, and are used to drive higher
voltage devices with a lower controlling voltage.
You can configure the following Relay output channel options:
z
You can choose to manually activate/deactivate the Relay output.
z
You can choose to manually activate/deactivate the Relay output and then specify that the Relay
output will either pulse (you get to specify the active and inactive pulse times) continuously or
for a specified number of pulse counts.
z
You can choose to manually activate/deactivate the Relay output and then specify a delay before
the output goes from inactive to active or active to inactive.
z
You can also specify a failsafe action that can either active or inactivate the Relay output when
the failsafe timer is triggered (see
Failsafe Timer Functionality on page 239
for more
information).
In an industrial freezer warehouse, the IOLAN A4R2 is used to monitor humidity transducers, which
are used to help prevent freezer burn. If the humidity reaches a certain percentage (monitored by an
Analog channel) a syslog message is sent to the Monitoring Application, causing the Relay channel
to activate an internal freezer dehumidifier. The Relay channel is deactivated when the Analog
channel sends a clear syslog message to the Monitoring Application and the Relay channel is
deactivated.
IOLAN
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rl
e
Monitoring
Application
Network
Industrial
Freezers
Relay I/O
Analog
Relay
Relay
A4D2
Analog