# Unable to read tmc uart 'stepper\_z1' register IFCNT **URL:** \ **Category:** General Discussion\ **Created:** [December 10, 2023, 6:25am UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197 "2023-12-10T06:25:12Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![backspace](https://avatars.discourse-cdn.com/v4/letter/b/e19adc/32.png) [@backspace](https://klipper.discourse.group/u/backspace)\ **Post date:** [December 10, 2023, 6:25am UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197/1 "2023-12-10T06:25:12Z")
### Basic Information: Printer Model: Custom Core XY MCU / Printerboard: BTT Octopus Pro V1.0 `klippy.log` [klippy.zip](https://klipper.discourse.group/uploads/short-url/j24fXidLjs44D0VTbJ68PvpDR2x.zip) (95.4 KB) I have a custom Core XY build that was set up and running on a BTT SKR Mini E3 V3. I soon found out that the SKR Mini didn’t have all of the features I needed, so I swapped the board out for a BTT Octopus Pro V1.0. I have two stepper motors on the Z axis that work as expected when they are connected to Motor2\_1 and Motor2\_2, which use the same driver, but if I connect the motors to Motor2\_1 and Motor3, so they run from separate drivers, I get a message saying: Unable to read tmc uart ‘stepper\_z1’ register IFCNT. The driver jumpers are all configured the same, so I’m guessing that it’s something to do with my Klipper config. Any help pointing me in the right direction is much appreciated. ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [December 10, 2023, 7:04am UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197/2 "2023-12-10T07:04:09Z")
According to [BIGTREETECH-OCTOPUS-Pro/Hardware/BIGTREETECH Octopus Pro - PIN.pdf at master · bigtreetech/BIGTREETECH-OCTOPUS-Pro · GitHub](https://github.com/bigtreetech/BIGTREETECH-OCTOPUS-Pro/blob/master/Hardware/BIGTREETECH%20Octopus%20Pro%20-%20PIN.pdf) your Z1 pins seem wrong. ---
**Author:** ![backspace](https://avatars.discourse-cdn.com/v4/letter/b/e19adc/32.png) [@backspace](https://klipper.discourse.group/u/backspace)\ **Post date:** [December 10, 2023, 7:42am UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197/3 "2023-12-10T07:42:07Z")
Thanks for the quick reply Sineos, I have the Z1 motor and driver plugged into the pins for Motor3. The image below shows the corresponding pins and config settings, is there something I’m overlooking? ![StepperConfig](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/3/32c8e829665b0819a88314367c5881053a28fc6b.jpeg) ---
**Author:** ![EddyMI3D](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/eddymi3d/32/1981_2.png) [@EddyMI3D](https://klipper.discourse.group/u/EddyMI3D)\ **Post date:** [December 10, 2023, 7:52am UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197/4 "2023-12-10T07:52:49Z")
Have you tried a different driver for Z1? ---
**Author:** ![backspace](https://avatars.discourse-cdn.com/v4/letter/b/e19adc/32.png) [@backspace](https://klipper.discourse.group/u/backspace)\ **Post date:** [December 11, 2023, 3:40am UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197/5 "2023-12-11T03:40:58Z")
Hey EddyMI3D, yes, I tried different drivers, thanks for the suggestion. ---
**Author:** ![backspace](https://avatars.discourse-cdn.com/v4/letter/b/e19adc/32.png) [@backspace](https://klipper.discourse.group/u/backspace)\ **Post date:** [December 11, 2023, 3:50am UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197/6 "2023-12-11T03:50:23Z")
I ended up moving the stepper\_z and stepper\_z1 connections to the Driver6 and Driver7 pins, now the Z motors work as expected. ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\ **Post date:** [January 10, 2024, 1:50pm UTC](https://klipper.discourse.group/t/unable-to-read-tmc-uart-stepper-z1-register-ifcnt/12197/7 "2024-01-10T13:50:39Z")
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