I am getting a 1085 fault on a TK tac 20. The controller says it is in normal service and sometimes other shutdown services but never latches hall calls. Should i reload the system software onto the cpu?

SPI error, wrong configuration of the LN node, bad cpu, can you see the node in IMS?
im not an expert, but i don't think you load the system software, maybe reload the LON configuration file, and the Car EEprom files, that were either saved by you, or left in the controller on a disk, or flash drive good luck

VG, it sure sounds like the SPI error.

500, are you showing any activity for LON outputs with IMS? F2, LN, L24, SPI cables and/or LON cables could be bad?

yes SPI error check all cables in the network and small boards

I've had Many of these flts. Check the 24vdc power supply. I was popping L24 cards every few days at one of my jobs and went through a few LN cards too. My voltage was 23.3vdc at supply and 22.75 at the farthest card. Bumped it up to 24.75vdc at the supply and it's been good for a year now. Verify on lon explorer that you are communicating with both channels (car and hoistway).

If you replace one or more of the L24 boards in the hall stations do the boards have to be programed with IMS tool or can it work strait out of the box?

L24's are just an expansion, no programming needed.