RS422/485 4 wire and RS485 2 wire with one IC

Status
Not open for further replies.
A

asadi.siyavash

Member level 4
Joined
Feb 14, 2013
Messages
68
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,288
Activity points
1,769
Hi,
I am really confused I saw some equipment that work with 2 wire and 4 wire RS485. they used same wire so they used one IC for converting. as you see in the picture

but as I understood from MAX3490 just can support four wire. how I can used it or some IC like this in both condition 2 wire and 4 wire without need any change in the PCB.
please help me,
all the best
Siyavash
 

i know but how can implement with something like MAX3490
 

You can't connect MAX3490 for half-duplex (two-wire RS-485) operation because it misses a tristatable driver respectively a TX-enable function. You can use e.g. MAX489 and your design must be able to generate the required direction information.
 

could you give me a shematic diagram of what you said? as you said user should manually select 2 wire or 4 wire communication? or not without any changes like above image it can work with 2 wire and 4 wire.
any help would be greatly appreciated.
 

I expect the product is using something like MAX1381, RS-422/485 transceiver with logic selectable half-/full-duplex mode.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…