1746-HSCE

[mac_g3 0]

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.

[P Daniil 0]

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.

[mac_g3 0]

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.