User manual

Digital Monitor AMC-1DBx Series User Manual
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6.13.4 Zone Operation.
The Zone programming allows a group of sensors to be applied to a dedicated set of
Alarm/Fail relays. This group could be located on a single floor of an underground parking
facility where the group of sensors controls the same ventilation component. The sensors
act as a group controlling these relays with the same thresholds set forth in their sensor
configuration. Any sensor of the group meeting or exceeding its gas concentration threshold
will trigger the assigned ventilation fan. If additional sensors have similar gas concentrations
no change to the fan is experienced. The ventilation fan will not be turned off until all
sensors in a group fall below their threshold. Additionally an analog output assigned to the
zone will track the zone’s average or peak gas concentration. A scenario for VFD fans is
described in the Analog Output Operation content below. Additionally, the zone contains
scheduled relay events whereby these fans can be activated during high use periods such
as a rush hour where fresh air is desirable. These scheduled relay events could also be
used by the facility during routine inspections.
6.13.5 Analog Output Operation.
The analog output is representative (average or peak) of the readings seen by all the
transmitters in a zone. The analog output is intended to control devices such as variable
frequency drive (VFD) fans, in which case the fans turn faster for higher gas concentrations.
6.13.6 AMC-1DA-RPT4 REPEATER
The AMC-1DA-RPT4 is a rugged, industrial-grade, optically-isolated RS-485 Hub / Splitter
/Repeater, which can be used to expand RS-485 networks by splitting one RS-485 network into
four, in turn increasing the maximum number of nodes and the distance covered by an RS-485
network. It was designed so that data coming from the input (RS-485) will transmit to all four
loops of RS-485 networks. However, each loop of RS-485 devices will transmit data back to the
input only, thus reducing any possible interference between each loop of the RS-485 devices.
Also, the failure of any individual loop will not affect other loops, making the RS-485 networks
more robust and reliable.
The product features opto-isolation circuitry, which effectively protects your RS-485 devices
from ground loops, transient surges, remote lightning and spikes. Opto-isolation also eliminates
ground loop and noise problems. The unit supports data rates up to 115,200 bps and features
data format auto-sensing and self-adjusting; therefore, no DIP switch or jumpers are required.
Three indicators (only visible when the enclosure door is open) are provided:
• Power Indicator
• Traffic on Slave Bus Indicator
• Traffic on Master Bus Indicator