Program Management, Timers, and Counters in Ladder Logic

[Technology]

https://www.youtube.com/watch?v=zTOOYWMJg9M . Specifically see 1:46 to 2:11.

3. The Cell PLC is in constant communication with two other field devices; the Cell Robot and Conveyor PLC. The Cell PLC communicates with the Cell Robot through the RobotInputs and RobotOutputs registers. The Cell PLC communicates with the Conveyor PLC through the ConveyorInputs and ConveyorOutputs registers.
4. System I/O:
a. Inputs
i. X0 – Cycle Start Button
ii. X1 – Cycle Stop Button
iii. X2 – Emergency Stop Button
iv. X3 – Perimeter Fence Gate Closed
v. X4 – Package ready for pickup at conveyor #1
vi. X5 – Package ready for pickup at conveyor #2
vii. X6 – Package ready for pickup at conveyor #3
viii. X7 – Package ready for pickup at conveyor #4
ix. X8 – Exit conveyor #5 full
x. X9 – Exit conveyor #6 full
xi. X10 – Exit conveyor #7 full
xii. X11 – Exit conveyor #8 full
b. Outputs
i. Y0 – System Running Lamp (Green)
ii. Y1 – System Error Lamp (Yellow)
iii. Y2 – System E-stop Lamp (Red)
iv. Y3 – Robot Running Automatic Operation (Blue)
c. Robot Inputs (Cell PLC -> Robot)
i. RobotInputs0-2 - Pickup Conveyor Selection (3-bit signal)
ii. RobotInputs3-5 - Place Conveyor Selection (3-bit signal)
iii. RobotInputs6 – Cycle Start
iv. RobotInputs7 – Cycle Stop
v. RobotInputs8 – Pick and Place Complete Handshake
d. Robot Outputs (Robot -> Cell PLC)
i. RobotOutputs0 – Robot Ready
ii. RobotOutputs1 – Robot Busy
iii. RobotOutputs2 – Robot E-stop
iv. RobotOutputs3 – Robot Cycle Start Handshake
v. RobotOutputs4 – Robot Pick and Place Complete
e. Conveyor Outputs (Conveyor PLC -> Cell PLC)
i. ConveyorOutputs0 – Place location for Infeed conveyor 1
ii. ConveyorOutputs1 – Place location for Infeed conveyor 2
iii. ConveyorOutputs2 – Place location for Infeed conveyor 3
iv. ConveyorOutputs3 – Place location for Infeed conveyor 4
f. Conveyor Inputs (Cell PLC -> Conveyor PLC)
i. ConveyorInputs0 – Conveyor 1 is full
ii. ConveyorInputs1 – Conveyor 2 is full
iii. ConveyorInputs2 – Conveyor 3 is full
iv. ConveyorInputs3 – Conveyor 4 is full

Program Requirements:
1. Count the number of packages picked from each of the four conveyors, and count the number of packages placed on each of the four conveyors. The result of each of the eight counters should be stored in registers D0 – D7.
2. Set the appropriate ConveyorInputs bit ON when sensor bits X4 - X7 are ON, to signal to the Conveyor PLC not to send additional packages until the robot has unloaded the conveyor.
3. The sequence of operations is as follows:
a. Packages arrive at random intervals on the four incoming conveyors, setting sensor inputs X4 – X7 ON.
b. The Cell PLC program will call the robot to pick up the package and place it on the exit conveyor. Once the robot has completed the pick and place operation, the PLC program will loop and call the robot to pick and place the next package.
i. Set the Pickup Conveyor Selection bits to a value of 1-4 according to which conveyor the package is to be picked up from. The Cell PLC may unload the conveyors in any order.
ii. Set the Place Conveyor Selection bits to a value of 1-4 specified by the appropriate ConveyorOutputs register.
iii. The PLC will then set the robot Cycle Start output ON until the Cycle Start Handshake is returned from the robot.
iv. The PLC will set the Cycle Start output OFF.
v. The robot will set Robot Busy ON, then proceed to perform the pick and place operation.
vi. When the robot is finished with the pick and place operation, the robot will set the Pick and Place Complete signal ON.
vii. The PLC will then set the Pick and Place Handshake signal ON. When the robot subsequently turns the Pick and Place Complete signal OFF, the Cell PLC will turn the Handshake signal OFF.
4. Create an additional subprogram called “System Status Outputs” and add ladder logic that performs the following functions. Call the new subprogram on the first rung of the Main ladder logic program.
a. While cell is actively running automatic cycles, turn on output Y0.
b. While any exit conveyor is not ready to accept a package, turn on output Y1.
c. While the emergency stop button input is OFF, turn on output Y2.
d. While the robot is busy, flash output Y3 on a 500ms pulse interval (500ms on, 500ms off).


Store a running count of the number of packages picked and placed on all four conveyors together in register D10.



Any help will be greatly appreciated! Thank you so much!
(Note: we normally use the 'Do-more Designer' program if that helps.