Eaton Easysoft plc claw machine program help

[trevor2939]

Hello all,

I am currently doing a project for a client. Where they want a custom claw machine built and programmed.

The ask is for there to be one button showcased on a pedestal, that when pressed once, launches a single axis trolley and hoist to randomized areas over a pit of boxes, lowers the hoist, raises it and returns to the home position. At this point the button is ready to be pressed again to restart the effect.

I am using the Eaton Easy 621-DC-TCX PLC with Easysoft basic v6.80
I have attached the program to the thread. I have 4 inputs a "stop pb", "cycle start pb", "cable hoist limit switch", and "trolley limit switch". As well as 4 outputs. "trolley motor forward", "trolley motor backward", cable hoist motor up", and "cable hoist motor down".

I have written the attached program and am pretty confident in the fact that it is working up until the point that the hoist and axis have to return to the home position. I have a homing routine at the beginning, but I am confused and stuck on how I should go about creating another marker for the final homing routine and how I should go about it. Any help would be appreciated.

Here is the program: https://www.dropbox.com/s/br3r4d4a23pv54r/Crane game rev1.e60?dl=0

 

[parky]

I suggest you use step markers as a sequence
First create a marker that implies it's at home position i.e. Trolley Home and Hoist up etc. Use this plus the Start button (one shot to stop people holding button) to set a bit as step 1, when conditions for step 1 have been met set anther bit for step 2 using the conditions like home, winch down and step 1 and reset step 1 bit to stop step 1 continuing (you could use a register with values 1-number of steps). do this for all steps including returning to home Each of the step flags are then used to drive the outputs

a simple example is:
Step 1 lower hoist
Step 2 Grab part
Step 3 Raise hoist
Step 4 Travel to position
Step 5 lower hoist
Step 6 Open grab
Step 7 Raise hoist
Step 8 Return home
so.. Step flags 1 or 5 lower the hoist
Step flags 6 or homing grab open flag, opens grab
Step flags 3 or 7 or homing raise hoist Flag, raise hoist
Step flag 2 grabs part
Step flag 4 travels to position
Step flag 5 or homing flag return home, travels back to start
For homing sequence you may need to open grab, raise hoist and travel back in a particular order

If out of position then use the not bit of home position marker and not any of the step bits on main sequence to initiate a return home. (only used in the event of a fault or system is not in correct position to start.
This may be a sequence
homing Step 1 Open grab (This will depend on if the grab has a part that may drop etc.)
homing Step 2 raise hoist
homing Step 3 go back to home.
If condition is met for any of these return sequences as it is in that position then they will automatically step on.
you could use one shot of start button so in homing sequence it only does one step every time the button is pressed (helps operator just say raise hoist if out of position then the operator can initiate next sequence.
I have done this on many pick & Place machines where we use one button for two functions and an auto man selector i.e. Man Run steps (one shot to run each sequence if in manual or start auto run on press if in auto.