RATGDO with Liftmaster Maxum JHDC

CoolBreeze · January 30, 2025, 7:36am

I have a Liftmaster Maxum JHDC model GDO. This is a commercial style opener, as the door is very large and heavy. In the wiring schematic of the RATGDO, it shows two leads to use with these types of openers. RATGDO refers to them as Discrete Open and Discrete Close. That’s all the documentation says. I’m not sure what to do with that. Do I just plug those two leads in parallel with my Wall Control wires? I’m concerned with over-volting the board and frying the RATGDO. Does anyone have any experience with this type of GDO? I have attached some supporting docs of my setup.

CoolBreeze · February 6, 2025, 7:45am

Bump.

I did some playing around with my setup, but was unable to get anywhere.

The Wall Control unit puts out 5-7 vDC. So There seems to be no issue with over volting the RATGDO. However, when hooking the RATGDO in parallel with the WALL CTRL leads, i did absolutley nothing.

So I tried using just a simple 18/2 bell wire using the SBC control, and I got no response as well.

Does anyone have any ideas how I should proceed?

raman325 · June 27, 2025, 5:01am

did you ever make progress on this? I haven’t tried to do it yet but I just got a Maxum JHDC installed and was interested in hooking it up to ratgdo.

I’m guessing the commercial wall control unit is significantly more advanced. If it’s the unit with the up, down, and stop buttons, there’s a ton more configuration available there. So my guess is the protocol they are using on those wires is different from the residential openers and that’s why you aren’t able to make it work. With that being said, I am going to try anyway because, why not?

Anyway, if you’ve made any progress, please share!

Tongboy · August 20, 2025, 7:10pm

you need to use the ratgdo dry contact mode.

buy the maxum auxrel board - ~35 online - I picked 2 up on ebay via offer for 40+ shipping.

wire the obstruction sensors like normal - sensor black → ratgdo → maxum

then ratgdo istatus door → open, istatus obst → close

configure the auxrel to have one relay on for close and one on for open and wire those into the open & close limit switches.

GND to common

reflash the ratgdo to dry contact firmware

…profit

without the relay board you’ll only get ‘trigger’ - no state. any other open/close sensors are MINIUM 20/piece and you need two of them. just buy the aux board so the open/close is all maintained in the opener and not separate.

The ‘not closed’ relay for me is the critical piece - so I can turn lights on when the door is opened and start a timer to turn them off when the door is closed if there isn’t anyone in the building.

tomato1 · September 30, 2025, 3:16pm

Has anyone found a way to connect ratgdo to the Maxum JHDC without the auxrel board?

Tongboy · January 7, 2026, 8:45pm

beware of the issue I ran into with ratgdo here - it’s real wacky on the maxum

github.com/ratgdo/esphome-ratgdo

maxum door opener opens on power cycle and generally doesn't work as expected

opened 01:59AM - 05 Sep 25 UTC

JeremiahChurch

## Components: v2.5i hardware d1 mini esp8266 firmware: 2025.7.2 dry contact … maxum JDHC opener - 2025 manufacture date, fresh firmware downloads wired based on #435 using an auxrel with the two relays setup as open and closed contacts. I also have a 5v relay & buck converter setup in the photo to use as an 'addon' to operate the separate 'stop' operation with a NC operation jumping the 'stop' input on the maxum that is normally always jumpered. It's unplugged for my basic validation testing. ![Image](https://github.com/user-attachments/assets/43f91b35-8701-45f1-ac56-24a106561a1d) ## exact wiring: https://cgi.widen.net/content/1wdhdwrodo/original/114-6042-000.pdf?u=mcyivk&download=true page 57 - old manuals don't show the full auxrelay configs aux relay 1 off on off - energizes at open limit - wired normally closed - COM to maxum COM - NC to open trigger aux relay 2 off off on - energizes when not at close limit - wired normally open - COM to maxum COM NO to close trigger obstruction sensors wired in. - blk to ratgdo TO OBSTR - jump from TO GDO to EYE on maxum - white sensor to EYE common on maxum open and close command contacts wired in with wire to common from same COM on maxum going to GND for limit switches on ratgdo. ## Operation: start door closed open and close limit switches both report correctly in HA. door closed limit switches report correctly-> press open in HA -> door goes up limit switches report both open during transition - stops at top - limit switches both report correct new status press door close button -> nothing happens -> HA ratgdo open limit sensor changes to off and door reflects as closing. Give it 30 seconds, press 'restart' in HA. ratgdo restarts. - limit sensors report the correct 'open' state in HA. press close in HA -> door closes, limit switches report both open during transition-> door finishes and limit switches report correct state in HA. pull the USB power plug, plug it back in - **door goes up!** The usb wire plug pull door goes up can also be reproduced without any of the auxrelay stuff plugged in. I think there is also another situation that will cause the door to go up related to wifi internet on/off for the ratgdo. I don't have reproduction steps but while wifi was going up/down repeatedly one day the ratgdo wired door was going up in line with the network cycles. initial guess is there an errant 'high' on the open pin during boot/power cycle for some reason? I'll pull some more logging with a machine plugged into the USB. I haven't looked at *any* code yet. I can *probably* use my 'stop' relay in a NO configuration to prevent any movement on boot, but I'd like to not need an additional relay for 'basic' operation - and a NO relay on the stop creates a pretty nasty failure scenario if the ratgdo dies/powers off. Happy to do any logging/testing that could help or provide any additional info.