A
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- Jan 1, 1970
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Not used RS485 before, so I need some advice please.
I am designing a control system where there is one master and 80
slaves on a RS485 system. The area I need to cover is some 200+ metres
square. The slaves will be scattered over the location in no
particular order. I was going to use standard twisted pair Cat5 cable.
My questions are
I have chosen the MAX487 chip for the driver/receivers, is this a good
choice?
I cannot daisy-chain the wiring because of the way the conduits run
under the roads etc. My only option is to run 4 "backbone" runs of 200
metres and take taps off these backbones, off to the slave modules in
a tree like fashion. Is this going to work?
Where do I place the terminating resistor?
Is it better to use shielded twisted pair cable or unshielded?
If shielded is the better option, do I connect the shield to mains
earth or to my 0 Volt supply?
Thanking you in anticipation.
Mark
[email protected] (remove the X to reply)
I am designing a control system where there is one master and 80
slaves on a RS485 system. The area I need to cover is some 200+ metres
square. The slaves will be scattered over the location in no
particular order. I was going to use standard twisted pair Cat5 cable.
My questions are
I have chosen the MAX487 chip for the driver/receivers, is this a good
choice?
I cannot daisy-chain the wiring because of the way the conduits run
under the roads etc. My only option is to run 4 "backbone" runs of 200
metres and take taps off these backbones, off to the slave modules in
a tree like fashion. Is this going to work?
Where do I place the terminating resistor?
Is it better to use shielded twisted pair cable or unshielded?
If shielded is the better option, do I connect the shield to mains
earth or to my 0 Volt supply?
Thanking you in anticipation.
Mark
[email protected] (remove the X to reply)