Hello All.

I'm French, and my English is not better !

I have a machine with SLC500 system, the PLC have a 1746-HSCE high speed counter module.

The machine is brand from the USA, the original encoder AB model 845H is broken mechanically.

Then, i want to replace the encoder with European model ( the brand is IVO industries ), model GI355 ,
with same type differential outputs, supply voltage ,and point per turn.

After wiring the nex encoder, the three signals a, b, and z is been present in the 1746-HSCE ..
i can see the led's turn on and off when i turn with my hand the encoder axe.

The 1746-HSCE increase or decrease counts normally with the rotation CW or CCW of the encoder,
but the accumulated counts .... is never reset to zero.

The settings of the 1746-HSCE is good and not modified ... after check, the reset module
is been with Z input only.

Next, i see in the 1746-HSCE manual ... the module need to reset correctly ...
at the end of each turn, the channel Z is true, and the channels A and B is false ....

My encoder not have the same waveform ... at the end of each turn, the Z channel is true .... if
the channels A and B is true ....

Anyone have idea to get a correct waveforms needed by the 1746-HSCE ?

Any help graetly appreciated.

Greetings from France,

Stéphane.

Greetings Stephane.

The exact position and length of the index mark (Z signal) in the A-B cycle is always a problem when replacing encoders.

As your encoder has differential outputs, try swapping the A with -A and B with -B encoder output wires at the controller input. This should change the A and B polarities (getting a high Z with A and B low), but with the side-effect of shifting the whole 360 degree cycle by half an encoder resolution cycle.

Normally this shift is not a problem in incremental encoder applications.

Good luck.

Hello P.Daniil.

Very thanks for your answer.

In first, because the longtime of the downtime of the machine, my boss
say me to search a reseller to purchase a original encoder 845H
( from Rockwell Automation ), and after mounting, the machine is now running ok.

Today, after machine ending production stop of the day,
the machine is off, i have a free time, and then i try to make your tip
(wire A+ swapped to A- , and B+.swapped to B-) with my encoder European model.

And ... bingo !!! ... all is ok ..!!! ...the accumulated counts is reset to
zero at the end of each encoder turn, the Z channel is been true
when the A and B channels is false.

This help is very great for me ... this is a best way to replace original parts from USA
( cost high .. and hard to find in France !! ), by European parts .... at low cost and easy
to find in France.

I again thank you very much for your precise and concrete help.

Thanks, greetings from France, and happy new year !



Stéphane.