am26ls32 line reciver doubts

[raman00084]

it is necessary to use a shunt resistor on the input terminals of am26ls32 ic?
if so what value of resistor i must use any formula?
my differential input voltage is 6v

what is the necessary of transmitting signals in am26ls31 and receiving in am26ls32, it is used in long distance wire communication?

i see this pair ic in motor encoders


what is the maximum distance of wire can be used in between 31 ic to 32 ic

 

[KlausST]

Hi,

AM26LS3... are RS485/RS422 transmitter and receiver.

The resistor is a terminating resistor.It is necessary. It must match to the cable impedance.
With RS4xx you have to use twisted pair cable wit an impedance of 100..120 ohms.

Google for RS4xx and you will find a lot of information. Also about distance..

The datasheets contain useful information, too.

Klaus

 

[betwixt]

... and the reason for using the 26LS31 and 26LS32 is they convert the input logic to a differential signal and back again. The advantage of differential signals (one is inverted the other is not) is if you use the correct cable which should have the wires twisted closely along it's length, you produce less radiated signal and also pick less interference up. This can be particularly important in motor control applications where long wiring may be close to strong sources of interference. It also allows for greater difference between ground potentials at the transmitting and receiving ends.

Brian.