EAW DSA250 & DSA230 - Manual (Page 39)

8 . 3 . 2 T E R M I N AT I O N N O T E S :
1. The DSA Terminate Switch connects a 120 ohm resistor as a load on the
EIA-485 cabling.
2. Normally, USB to EIA-485 or RS-232 to EIA-485 converters also have a
termination resistor connected as a load on the computer end of the
EIA-485 cabling. If optional, this termination should be switched on. Both
this termination resistor and the one in the loudspeaker at the far end of
the EIA-485 cabling from the computer are required to ensure proper
network operation.
3. Due to inherent current limitations, the load resistance on EIA-485 hardware
must be greater than 50 ohm. This means only ONE loudspeaker Terminate
Switch can be “ON” on the EIA-485 network along with the converter’s
termination resistor. If more than one loudspeaker Terminate Switch is
“ON”, the network can experience intermittent or non-existent communications.
Additional terminations needlessly draw more power from the RS-485
converters, reducing signal strength.
4. The Terminate Switch only works for the EIA-485 cable connection at the
Phoenix Contact connector. The Terminate Switch does not work for
EIA-485 connections between loudspeakers using the Signal Link connectors.
Therefore, use the Terminate Switch only on the loudspeaker within a
cluster that is connected to the network via the Phoenix connector.
8 . 4 S u p p o r t F o r E t h e r n e t
The infrastructure for a CobraNet™ network must be designed and built using
standard IEEE 802.3u 100BASE-T Ethernet network hardware. As this is a
standardized technology, EAW does not provide technical support for Ethernet
networking. Standards and technical documentation for the design, set-up,
operation, and troubleshooting of 100BASE-T Ethernet networks are available from
a variety of sources on the Internet.
8 . 5 S u p p o r t F o r C o b r a N e t ™
CobraNet™ technology relies on specific and exacting network timing issues to
deliver digital audio to its destination intact and with no dropouts. As such, there
are certain limitations to how an Ethernet network for CobraNet™ can be designed.
For specific information about designing a CobraNet™-compliant network, contact:
Peak Audio (A Division of Cirrus Logic)
305 Interlocken Parkway
Broomfield, CO 80021-3484
Phone: 303-466-5228
Fax: 303-464-6776
E-Mail: [email protected]
Web: http://www.peakaudio.com
NOTE: Peak Audio’s web site provides, on-line information about designing an
Ethernet network that complies with CobraNet™ requirements. It also provides
links to information about Ethernet technology.
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