Hello, I am working on a Dover T4 and am having trouble getting the elevator to pass a NTST/NTSB ETSB/ETST. Also I am having a problem with OS tripping randomly.

For the NTS/ETS i have replaced the transducer head on the car top. I have replaced the modules on the PMI card. I have tried replacing the CPU and DSP board.

For the OS tripping I replaced the governor encoder sensor.

Not sure what else to do here.

Tape guides (define position relative to switch activation) New scan of Hoistway?? Switch position, switch rollers,

Hi Otis,
What is the reason your not passing the tests? is the NTST not slowing down in time/or not at all to reach the terminal landing? is the ETS dropping too late and your fully compressing buffer?

Are the slots in the vanes clean?? Have the vanes been moved?? Are you testing the NTST/ETST and the unit is failing, or are you trying to setup the NTST/ETST and the setup is failing? Have any parameters (DEC, etc.) been changed??

Hello we had to move the vanes and change the NTS5 parameter in order for it to accept the the learn run for NTSD/ETSD. Now we are fighting a fault 54 which is a BK MC detected out during a run. Would you happen to have any info on this. I have replaced all the modules associated with these two relays.

Check the NTs and ETS values to be sure your scan took.
NTST (top) and NTSB(bottom) command as well as ETST And ETSB no value=no scan. I would also check the distances between slowdown vanes is set correctly.

Usually I ended up replacing both BK and MC to eliminate fault 54. Not sure that’s going to help with NTS or ETS but it seems like sometimes when you fix what you see, then the other problems just go away. Good luck

Check your MXV parameter (maximum number of vanes).
I have seen a bad EEProm keep changing this parameter on power ups. So this is configured to look at a specific amount of ETS/NTS checkpoints per your job. As an example it might be looking for 18 readings at the top or bottom. If MXV changes you will never get a proper backup scan.