
Figure34-NetworkingMultipleSystemsTogether
1)ThediagramaboveillustratestheMasterinthemiddleoftheRS485buss.
ItisnotnecessarytoplacetheMasterinthemiddle,itcanbeplacedanywhereontheline.
2)Besureoneendoftheshieldfromthetwistedpairwireisscrewedtothemountingstudinthelower
righthandcornerofthecircuitboard.
3)Eachsectionofwiremustbegroundedatonesideonly.
4)WhenattachingthewiresfromtheSystem2’sinthenetwork,polaritymustbeobserved.
5)ThewirelengthfromthefirstSystem2circuitboardtothelastcircuitboardinthenetworkcannot
exceed4000feet.Additionalcircuitboardscanbeplacedanywherewithinthis“string”.
6)A120ohmresistormustbewiredinparallelwiththetwowiresonthefirstandlastunitson
theRS485buss.
7)MaximumRS485busslengthis4000feet.
8)TosetupthenetworkingconfigurationrefertotheProgrammingChapterandOption#18.
SLAVE#1 SLAVE#2MASTER
120OHM
RESISTOR
120OHM
RESISTOR
22GAUGESHIELDEDTWISTEDPAIR
22GAUGESHIELDEDTWISTEDPAIR
SHIELD
SHIELD
NOTCONNECTED
SHIELD
NOTCONNECTED
SHIELD
14 15 14 15 14 15
Comentarios a estos manuales