# Signals of a 5V encoder

H

#### Haritztolete

Jan 1, 1970
0
Hi, I am going to use a 5V encoder of 600 pulses. The signal it gives
me is a pulse train of 5V and it goes to a driver that is 25 metres far
away from the encoder. The cable of the encoder goes close to some
power cables and all the cables are shielded. I don't have any
experience in such long distances and I would like to know if I could
have problems with electric noise, and how to avoid it. Thanks a lot.

C

#### [email protected]

Jan 1, 1970
0
Haritztolete said:
Hi, I am going to use a 5V encoder of 600 pulses. The signal it gives
me is a pulse train of 5V and it goes to a driver that is 25 metres far
away from the encoder. The cable of the encoder goes close to some
power cables and all the cables are shielded. I don't have any
experience in such long distances and I would like to know if I could
have problems with electric noise, and how to avoid it. Thanks a lot.

You will have trouble, use a RS232 line driver near the encoder to
change the signal levels and a reciever at the other end to change them
back.

C

#### Chris

Jan 1, 1970
0
Haritztolete said:
Hi, I am going to use a 5V encoder of 600 pulses. The signal it gives
me is a pulse train of 5V and it goes to a driver that is 25 metres far
away from the encoder. The cable of the encoder goes close to some
power cables and all the cables are shielded. I don't have any
experience in such long distances and I would like to know if I could
have problems with electric noise, and how to avoid it. Thanks a lot.

Hi, Haritztolete. I hope you haven't purchased your encoder yet. If
you haven't, look for one that gives you a line driver output. You can
then set up a line receiver at the other end of the twisted pair line,
and change the signal back into standard digital logic. A standard
open collector output will be a noise nightmare at 25 meters, no matter
what the pullup resistor.

A line driver/line receiver setup will provide quite a bit of immunity
from noise, because the noise is equally coupled into the both sides of
the differential pair if you use twisted pair wire. The difference
between the two voltages will still be the same, and that's what
determines the logic level.

However, you also have to worry about sufficient energy being
inductively coupled into the signal lines to cause damage to the line
driver or line receiver. You really should arrange for different
routing of signal and power lines as a matter of course, shielded or
not.

Trust me on this one. There are few things more dispiriting, or more
expertise, than creating solutions that kind of work or break down at
random.

Please post back if you have any questions.

Good luck
Chris

J

#### Jasen Betts

Jan 1, 1970
0
Hi, I am going to use a 5V encoder of 600 pulses. The signal it gives
me is a pulse train of 5V and it goes to a driver that is 25 metres far
away from the encoder. The cable of the encoder goes close to some
power cables and all the cables are shielded. I don't have any
experience in such long distances and I would like to know if I could
have problems with electric noise, and how to avoid it. Thanks a lot.

use twisted pair cable (eg one pair from a cat-5 cable) and put a
optocoupler and suitable resistor on the far end.

Bye.
Jasen

E

#### Eric R Snow

Jan 1, 1970
0
Hi, I am going to use a 5V encoder of 600 pulses. The signal it gives
me is a pulse train of 5V and it goes to a driver that is 25 metres far
away from the encoder. The cable of the encoder goes close to some
power cables and all the cables are shielded. I don't have any
experience in such long distances and I would like to know if I could
have problems with electric noise, and how to avoid it. Thanks a lot.
Greetings,
I am not an electronics expert by any means, just a rank beginner. But
in the last year I have been using encoders for some custom
applications and have learned quite a bit about them. Nearly all this
knowledge came from US Digital. Their website is USDigital .com. I
think. Anyway, they sell a device for connecting encoders to long wire
runs. The prices are from $11 to$34 for these cable drivers. Here's
your questions and can tell you if their device will work with your
encoder. They were able to help me connect a twenty year old encoder
to one of their displays. Anyway, I'm just a satisfied customer. No
connection to them other than that.
Cheers,
Eric R Snow,
E T Precision Machine

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