terminators in RS-422 ?

[small_chip]

I've got a view from a link about RS422:
**broken link removed**
this post has mentioned about terminator (end resistors) , i haven't been clear why we need terminator ?
hope someone can help me ! ^~^

 

[IanP]

I've got a view from a link about RS422:
**broken link removed**
this post has mentioned about terminator (end resistors) , i haven't been clear why we need terminator ?
hope someone can help me ! ^~^

**broken link removed**

:wink:
IanP

 

[small_chip]

Thanks IanP! i would like to ask you that: "why it is not good if the transmited signal is reflected from the receiving terminal ?" ! maybe that seem stupid but hope for your reply !

 

[betwixt]

A reflected signal will appear across the wires just as the outgoing one but due to the propagation delay it will at best be out of step with it and in worst case may partially cancel it or later later data bits. The reflection may add or subtract to the other signals on the wire, either way it 'dirties' the signal and reduces it's integrity.

Brian.