GEC Multiplexed push unit : LUSENET : Elevator Problem Discussion : One Thread

Hi, We want to modernize the GEC lift Car operating panel so I want to know how the multiplexed push unit working? What is the voltages for switch and LED? Here we got lines marked with P,P+,L+ for every push unit.Is it possible to replace that with 24v push unit? Please help me.

-- elevguy (, March 02, 2005


contact me on 01274 254 234

-- geoffjudge (geoff,, March 03, 2005.

Hi Mr.Geoffjudge, Hope you are doing fine Iam from singapore so calling you will be difficult. Is it possible to explain through email? If you do this I will be thankful to you. Regards

-- (, March 04, 2005.

For the landing pushes, from the multiplex output you will find that "5" feeds the bottom, third,sixth,ninth,pushes etc "6" will feed first, fourth,seventh, tenth, pushes "7" will feed second, fifth, eight, eleventh,etc and these feed back down the data input to the micro processor by the "P+". The "L+" output from the push, go to the position indicators by joining the output data from the processor. These are the VRX pushes and they have a small printed curciut board in them.

If you are retaining the main controller and indicators you need to retain these small boards but it is possible to change the pushes and mount the boards seperately. If you are replacing the main controller you need to run the wiring to each push as per the drawing of the controller supplier. Terminal "5" from the multiplex output is also terminal "K" on the position indicator so you can't replace the controller and keep the original indicators.

I have a clear copy of the wiring for these that I can fax if you require

-- geoff judge (, March 07, 2005.

Thanks Mr. Geoff judge for the details. Here we are changing only car operating board rest all remains the same. I got the drawing but I canít understand the operation. The 'P' is looped to 8 push units as common. The data line P+ and L+ is not going to the PCB separately for every push unit it is shared with other unit. For example 8th 16th 24th push unit L+ is looped together and going to the PCB as a single line, same for P+ also. So what is my doubt is how the microprocessor differentiating between 8th 16th and 24th push unit data? What will be the voltage between P and P+ then P and L+? Since it is different from discrete push units and serial communication push units used in other company lifts I want to know the operation of this unit.Thanks again.

-- (, March 07, 2005.

From memory, the push feed from the multiplex output on "3" and "4" are half-wave and are polarised in the opposite direction, so lowest level and the next level car push outputs can be joined together to return to the input. If both calls are pressed the input is full-wave if only 1 push is pressed then the input is half-wave either + or -. At this point, I hope my memory is correct, but I am sure someone out there will let us know if I have remembered incorrectly.

-- geoff judge (, March 07, 2005.

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