You need to find the LN card for the hall. Either in the controller or a box in the hoistway. If you have the 1085 SPI loop error the LED will be flashing fast meaning error. Slow flash rate is what you want. First turn around all of your fixtures, button and lantern and inspect the L24 cards and CAT 5 ends. If you see anything bad, replace it. Sometimes you have to take a known good L24 card and swap it in one at a time to see when you get a good flash rate back. Could also be a cable. You can use a cable tester to test each cable. A lot of times the problem is at or just before or after the fixture that has its light on all the time. Could also be the LN itself but rule out everything in the loop first. To replace the LN you’ll need LON config file and LON Talk tools.