text: <s>[INST] PF755 with UFB feedback card connected to full digital SSI IFM encoder model RM8001. Bad velocity feedback. PF755 20G11NC060JA0NNN, firmware 16.002 20-750-UFB-1, firmware 1.015 I'm testing a lifting application. In this application is very importat to know the position of the load. In order to know load position, we read feedback position of motor encoder. If we use a simple incremental encoder, every drive disconnection implies to readjust home position. To avoid this, we choose an absolute encoder. To reduce the number of wires from the encoder to the drive, we choose an absolute full digital SSI encoder (IFM model RM8001). In the drive we have a 20-750-UFB-1 feedback card. This card is able to read SSI devices. We connecte SSI encoder according to Document ID BF14673. But parameter 6 equal to 9 (SSI FD ChX) We programmed UFB card according to Document ID QA28660 Parameter equal to 9 (SSI FD ChX) Parameter 8 equal to 0 Parameter 20 equall to 4 (Gray code) Parameter 21 equal to 12 (4096-12 bits per revolution) Parameter 22 equal to 13 (8192-13 bit number of revolutions) Now, UFB car shows the position from encoder with no errors. If i move drive the count changes increasing or decreasing depending movement up or down. The next step, i configure drive. I follow Document ID QA15265. In this document, after basic motor data programing. Is necessary to program feedback data. But prior to this we must check feedbak. So we write in parameter 132 a 40005 (Port4: Feedback 0) then, i move in VHz the drive monitoring paramenter 134. PROBLEM Te speed i see in parameter 134 is bad. Not stable, like ramdom. Numbers i'm not able to understand. For example, i move drive at +10Hz. In parameter 134 appear number between 0 and 1500 more or less. The accuracy is better if i write in paramenter 133 a 7 (3R/S noise) then in 134 i read from 0 to 16. In parameter 26 of UFB card i tested all possible values to sampling time, but results are simmilar. Where do you think is my problem? Thanks [/INST] Have you tuned the drive or the speed loop yet? Based on your pretty detailed post (thank you, btw) you really only got to the point where you are doing a direction check. and have not actually tuned the drive or the speed loop in QA15265. Based on your post, this is where you stopped: Which is only to check the direction of the encoder, not a final speed feedback check. If I misread your post, I apologize. Regards, RM \\n </s>