8 . 3 E I A - 4 8 5 N e t w o r k
EIA-485 network cabling has certain limitations that these notes summarize. Improper set-up of an EIA-485 network can result in faulty or no operation. To use EIA-485 network configurations or cabling schemes not addressed in this manual, consult a qualified network professional.
8 . 3 . 1 C A B L I N G N O T E S :
1.Single Loudspeaker or loudspeaker cluster:
One end of the EIA-485 cable is connected to the computer’s EIA- 485 port and the other to the EIA-485 connector on the loudspeaker or on one of the loudspeakers in a cluster.
2.Multiple Loudspeakers:
One end of the EIA-485 cable is connected to the computer’s EIA- 485 port. The cable is then connected daisy-chain fashion to multiple loudspeakers or clusters. This means to connect the EIA-485 cable from the computer to a loudspeaker or cluster, then to loop it to add- itional loudspeakers or clusters. Use the supplied RJ-45 Signal Link Cables to link loudspeakers within a cluster using the Signal Link jacks. This cable also interconnects the audio between the loudspeakers.
3.DO use an EIA-485 hub when separate EIA-485 home runs to the computer are needed because of cable routing constraints. Note: EIA-485 hubs often contain an RS-232 to EIA-485 converter.
4.DO use an EIA-485 hub to extend the length of the EIA-485 cabling beyond 1000 ft / 300 m. Literature about EIA-485 claims maximum cable lengths of 4,000 ft. However, the fastest data rates for a DSA network, assuming ideal network conditions, limit the maximum to 2,800 ft / 850 m. Performance variations for the network cable, connectors, EIA-485 drivers, and several other variables can and often do further reduce this length. Therefore, this is the maximum recommended length to ensure reliable communications.
5.DO use an EIA-485 hub to connect the EIA-485 network to more than 31 DSA Clusters. Each loudspeaker within a multi loudspeaker DSA Cluster counts as one DSA Cluster if they are all connected DIRECTLY to the EIA-485 network using the EIA-485 Phoenix connectors. If the loudspeakers within a multi-loudspeaker DSA Cluster are inter-connected via the Signal Link connectors, and thus only one is connected directly to the EIA-485 network, then this counts as only one DSA cluster.
6.DO NOT connect the EIA-485 cabling to the loudspeakers in a star fashion. This means do not home-run an EIA-485 cable from each loudspeaker or cluster to the computer.
7.DO NOT connect the EIA-485 cabling between loudspeakers in a star fashion. This means do not run an EIA-485 cable from one loudspeaker or cluster to more than one other loudspeaker or cluster.
8.DO NOT connect loudspeakers or clusters in a “stub” fashion. This means do not connect a branch cable off an EIA-485 cable to run to a loudspeaker or cluster.
9.DO NOT connect the far end of the EIA-485 cable back to the computer. This means do not make an electrically closed loop for the EIA-485 cabling.
