Hey there, I’ve got a Elevator Controls IECA H-900 that I’ve been fighting a communication issue for the past month. Started out with the doors not opening fully. I’ve got an ATS door operator but I confirmed that the door board is not the issue like it is most of the time on these units. The doors will open about half way and then the car would lose communication with the top of car board is what the P8 board said. About 30 seconds later the car will regain communication and the doors will work properly. We checked the TOC board and it was in fact dropping the DOF pilot for the relay which led us to believe the TOC board was bad (Confirmed it wasn’t the DOL malfunctioning or any other input that would drop the DOF). So, I ordered a new TOC board from EC. Installed it today and the issue persisted. I changed the TOC software chip from the old board into the new board. No change. Changed the communication wire connectors on both ends, in the controller on the P8x and the TOC side and checked my connections. No change. Swapped my P8 and P8x boards and checked all my Params. No change. Changed all of the communication chips on my P8x and TOC and COP board. No change. I’m about out of ideas here for why this elevator could be intermittently faulting out with no communication with the top of car. Got any ideas People??