If you have the schematics, you will need an electronics expert, there are to many wires to be wired properly and any mistake will end up in tears.
No amount of pictures will help you if you are not sure what each wire there does.
Start by studying the schematics with someone who knows electronics, check the schematics and the physical wires, find where each of them is located and how it is connected, especially the following:
Find the E-stop loop and figure out how it connected to the computer, you will have to wire this to the 7i77 input later.
Find the Enable wire that goes from the computer to the drives ( drives are in small boxes near the motors, not in any of the machine enclosures ), you will need to connect this to a 7i77 output later.
Find the analogue inputs for each servo drive, there are 3 drives so you will need to find all 3 of the cables to connect them to the 7i77 analogue outputs.
Find the encoder wires from all 3 servo motors, this is easier as they are separate for each motor, to be connected to 7i77 encoder inputs.
Find the limit switch cables, there are 3 of them used for homing and limits, to be wired to 7i77 inputs.
There is another extreme limit switch under the gantry on the left side when looking from the computer's side, do not touch this one and do not wire it to anything !!!!! This one cuts all the interlocks and power to drives in case of run away !
Keep in mind that making the interlocks work will need wiring on the big box located on the gantry, as they are controlled by several voltages, e-stop and enable. If i remember correctly there is only a single wire involved but i can not recall how and where, it was very hard to find it.
All the wires have labels, there are also numbering of each and every connector in the schematics, except there was an error on this documentation that had me chasing two connectors for over 3 hours, they are labelled wrong.
Topic Author
