Raspberry p15 and linuxcnc 2.9.4 spindle speed

Hello I have Raspberry pi 5 and byte 2 bot hat on my mill and it works very fine and now i try to convert it to my lathe with a problem with the spindle speed reading and the index and phase a for cutting thread in the lathe . I have tried to read and understand the Hal mystery with a minor of luck . In Hal Meter i there are a signal at => lowpass.0.in but reading zero at  lowpass.0.out  => abs.0.in pyvcp_options.hal . Can somone helpfull help me with this problem / krister