Sorry for my limited English ability and Technical ability.
It is very common in our company that, the engineers don't care about (or don't know) the termination resistors on a CAN-Bus. They just simply put one 60-Ohm resistor between two or several CAN-Devices (mainly for testing purpose). I know this is not standard, and I don't like this workaround. I tried to figure out why such a workaround is bad, but failed.
It seems that many engineers use such a workaround. ==============================> www.microchip.com/.../m177894-print.aspx a single 60 ohm termination for lab testing when bus is only a few feet (probably not allowed, but it works).
www.microchip.com/.../m144034-print.aspx If you don't have two 120-ohm resistors, you can accomplish the termination (on a small network) with a single 60 ohm resistor(120 in parallel with 120 is 60) or anything close 55-65 is fine. <==============================
I found a document saying this workaround is a mistake, but it does not provide why. ==============================> www.scribd.com/.../SAE-J1939 The bus is linear and should be terminated with 120-Ohm resistors at either end. It is a common mistake to use one 60-Ohm resistor instead of two 120-Ohm resistors. This does not work correctly, however. <==============================
What is the disadvantage/mistake, if we use one 60-Ohm resistor instead of two 120-Ohm termination resistors on a CAN-Bus, assuming the communication distance is not very long and only 3-5 CAN-Nodes (Devices) involved? In another words, when will such a workaround fail to work?
-- It is very difficult to find another job in southern Taiwan. So I am still struggle with idiotic things, and busy in urgent projects.
And the echo may change the word unknowingly. everyone hears a wrong word without any problem noticed.