linear encoder count doubles going reverse than forward

[Famus]

Hi, I have a quadrature linear encoder. I hooked it up with a PCI-MIO-16E-4 (aka PCI-6040E) according to the tutorial. Forward motion works great. But reverse motion have decrementation twice as much as it should. I have it hook as: A to PFI8, B to DIO6 and using counter 0. Can anyone please tell me what is wrong? Thanks alot!Famus

[Hillman]

Hi Famus&nbsp;&nbsp;Using quadrature encoder with PCI (i.e. not cDAQ) use connect Channel A to the source input of counter x (coutner 0) which is PFI8 as you said.However, for B, you need to connect to the up/down line - im not sure if its DIO6. But check your connections and make sure you set the counter for simple edge counting and set the active edge to falling.&nbsp;<a href="http://zone.ni.com/devzone/cda/tut/p/id/4623" target="_blank">link </a>- about your set up - maybe its vibrations? &nbsp;Please reply soon,Regards&nbsp;

[Corby_B]

Hello Famus,&nbsp;Thanks for your post!&nbsp;I would like to ask if you are using digital lines 0-5 while also trying to use your encoder on line 6? If this is the case there might be a setting you will have to change to make this work correctly. Its not the same exact behavior but take a look at the following knowledge base that talks about this issue.&nbsp;<a href="http://digital.ni.com/public.nsf/allkb/0165B8138918F12586256B09005CA3A3?OpenDocument" target="_blank">Using the Open Digital Lines on an E-Series DAQ Board when Taking Encoder Measurements </a> &nbsp;Let us know if any of this information helps you with your problem!&nbsp;Cheers!&nbsp;Corby_Bhttp://www.ni.com/support&nbsp;