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Modular ARCs
Remote ARCs
The ARC ports distribute power and RS-485 data to one or more
ARCs arranged in one or more chains over standard CAT5 cable. Most
Symetrix products with an ARC port can power from two (2) to ten (10)
ARCs. (Please see the individual products’ documentation for specific
details.)
WARNING:
The RJ-45 connectors labeled “ARC” are only
for use with the ARC series of remotes. DO NOT plug
the ARC connectors on Symetrix products into any
RJ-45 connector labeled “SYMLINK”, “ETHERNET” or
“COBRANET. The “ARC” RJ-45 connectors on Symetrix products
can carry anywhere from 6 to 24 VDC which can damage SymLink,
Ethernet and CobraNet circuitry.
ARC Network Design
The ARC can be powered two ways: (1) over CAT5 via the RJ-45
“ARC” port on ARC-enabled Symetrix products, or (2) by local 6 to 24
VDC power supplied to the ARC’s terminal block connections.
The ARC’s power requirements vary depending on the voltage supplied
to it. At 15 VDC, it uses approximately 115 mA, while at 6 VDC it uses
approximately 300 mA maximum. As the voltage goes from 15 to 6
VDC, the current requirement increases accordingly.
ARCs can be daisy-chained and fed power over this daisy-chain
from the ARC port. However, as the length of the cable increases, so
does the resistive line loss, which lowers the voltage available at each
subsequent ARC. The actual power drain on each output from an ARC
port can vary substantially depending on the number of ARCs and the
distance each of them is separated by. In order to assist with system
design, Symetrix has available a Microsoft Excel spreadsheet that can
help a system designer determine power requirements based upon
cable length, number of ARCs and the power supply to be used. This
spreadsheet can be downloaded from the Symetrix Technical Support
pages at: http://www.SymetrixAudio.com.
The following table gives some indication of cabling limitations, based
on DC power only (the following table is only relevant for the
RJ-45
ARC port
when powering the ARC-2 from the ARC-PS): minimum stated
distances assume 28 gauge CAT5 cabling, maximum stated distances
assume 24 gauge CAT5 cabling.
If power is not distributed over CAT5, each RS-485 chain will be limited
to 1000 ft in a star network configuration and 4000 ft in a daisy-chain
network configuration. Longer distances may be possible using third
party RS-485 extender products.
Disclaimer:
From time to time we test the compatibility of our own
products with those of third parties. While we are happy to share with
our customers the results of our own studies as well as other possibly
unsubstantiated information regarding these third party products,
it is the policy of Symetrix, Inc. to neither endorse, recommend nor
support products manufactured and/or supplied by third parties. The
responsibility of choosing third party products which are compatible
with Symetrix products rests solely with the qualified contractor,
consultant or system designer.
WARNING:
When designing a system, one must be careful
not to double power any ARCs. If all pins on the CAT5
connections are used, power can travel over the CAT5
cable and reach any ARC on that particular chain. So,
power over CAT5 could potentially come from the
originating ARC port or from an ARC that is powered locally and then
daisy chained via CAT5 to other ARCs. In general, it is recommended
to use only one type of connector on the ARCs, either the RJ-45s (with
CAT5 cable) or the terminal blocks
ARC Audio
ARC Audio
provides a means to take a single balanced analog audio
line and either inject it into or pick it off an RS-485 network’s CAT5
cable run. An ARC Audio port on a Symetrix device may be wired to
a nearby device’s analog input or output. This provides a means of
easily running a single audio channel to or from a remote source or
destination. The ARC-MIC and ARC-XLR make use of ARC Audio to
transport audio signals back to a Symetrix rack mount device.
Note 1:
The original Menu ARC remote (simply named “ARC”) does not
support ARC Audio lines and will ground the audio lines if connected.
Note 2:
To avoid the possible grounding, mixing, or shorting of the
ARC Audio lines, it is recommended to home run any ARC devices
making use of the ARC Audio lines so that only one ARC device is on
each chain.
ARC PORT PINOUT (both Grounds and
Powers required for specified distance)
Pin #
Function
1
Audio (+)
2
Audio (-)
3
Common Ground
4
RS-485 Data (A)
5
RS-485 Data (B)
6
Common Ground
7
Power (+V)
8
Power (+V)
Note:
The ARC Audio lines may be grounded at the Symetrix Rack-mount
device and the ARC wall panel to provide additional distance.
ARC Network • ARC Audio
