Step 2 – Operator Inserts Cocks Tool PLC will not start cycle until the prox switch is made and the operator presses the start button Prox Switch Prox switch uses the crowsfoot for it’s target Crowsfoot
Step 2 – Cocked Tool Zoom Nut is held away from equalizer allowing the cable force to be measured by the load cell Balls lock into the detent in the nut Slide ring snaps forward and balls lock the piston in the retracted position Load Cell measures cable tension
Nut Runner Control 1.Applications 1,2,3 are used for the initial fast run and are set for 400, 600, and 800 RPM respectively. These applications are also set to only run long enough to stop running before the nut reaches the end of the threaded rod. 2.Applications 5,6,7,8,9 are used for running slow forward and are set to 50, 100, 150, 200, 250 respectively. 3.Applications 11-111 are used for the final reverse revolutions. These are used to back the nut up a exact number of revolutions ranging from 1-100 revolutions. Example: application 41 will run reverse for 31 turns then stop. 4.Applications 112-115 are used for manual, calibration, and verifications modes. 5.In the parameter set up screen each of the nut runner parameters references a specific application. For example if the fast run speed is set for 800, slow run speed is set for 100, and reverse revoultion is set for 30 then the fast run portion of the process will use application #3, the slow run portion will use application #6, and the reverse revolutions will use application #40. The Nut runner controller has 115 applications defined that are selected by the PLC to perform specific portions of the tensioning sequence.
Tensioning Cycle Control Sequence Page 1 1.When start trigger is pulled the PLC starts the cycle if the prox switch is made. If prox is not made a “tool not cocked” fault is set. 2.Based on the fast run speed selected in the parameter set up screen the PLC select application associated with that speed (app 1, 2, or 3). 3.The PLC then initiates the fast run by turning on the controller’s run bit. 4.The PLC monitors the load cell inside the end effector and continues running fast forward until the specified run fast force target is achieved. Once the target force is achieved the run bit is dropped. 5.The PLC then sets the application associated with the slow forward speed specified in the parameter setup screen (app 6, 7, 8, or 9) 6.The PLC then turns the run bit on and monitors the load cell force. 7.Once the force measured by the load cell force achieves the overshoot target (= target tension + overshoot) the PLC turns off the run bit and continues to monitor the cable tension measured by the load cell and starts a “stable force” timer. This timer duration is specified in the parameter screen. 8.If the force drops below the restart force (= target force – restart delta) before the “stable force” timer is done then the PLC turns the run bit on and repeats steps 6-8. 9.If the force is above the restart force and the stable force timer is done then the system is stabilized and the tensioning part of the sequence is done. 10.There is also a maximum cycle time timer that limits the total time that can be used for the tensioning portion of the sequence. If this max time is exceeded the tensioning part of the sequence is terminated.
Tensioning Cycle Control Sequence page 2 11.When the tensioning part of the sequence is complete then the tension in the system is evaluated and compared to the upper and lower limits. If the tension is within the limits then the job is accepted and the reverse revolutions part of the sequence is executed. If the tension is outside the acceptable limits the job is failed and a fault is set (either final tension too high or final tension too low) 12.If the tension is within the acceptable limits then the PLC sets the appropriate application to run the number of reverse revolutions specified in the parameter screen (apps 11-111). 13.The PLC then turns the run bit on and waits until the job complete OK bit is sent back from the nut runner controller. 14.Once the OK bit is received the PLC then accepts the job, sounds the job complete chime, turns the green indicator light solid, and sends job passed information to the error proofing system.
Fast Run Faults 1.Fault #4, Tool Misload. This occurs if a specified minimum amount of force is not seen by the load cell within a specified amount of time. The minimum force at the time are specified in the alarm setup screen. This fault indicated the operator did not get the nut fully seated before cocking the tool. 2.Fault #11, Tool Removed During Fast Run. If the release ring is pulled during the fast run portion of the cycle, the force being measured by the load cell will drop suddenly and the prox switch will go open. If these two condition are occur then this fault is set. 3.Fault #3, Fast Run Rotation Limit Exceeded. If the nut runner controller sets the job complete OK bit before the load cell force reading achieves the run fast tension target then this fault code is set. This is usually an indication that the cable system was not connected properly. 4.Fault #18, #19, Nut Runner Over Torque. If the nut runner exceeds the maximum allowed torque it will shut down and set the job complete NOK bit. If the PLC receives this fault it will evaluate the tension in the cable system if the tension is in the acceptable range then the cycle continues and an Over Torque Warning (#18) is set. If the cable tension is outside the acceptable range then an Over Torque Fault (#19) is set and the job is failed. The PLC monitors the load cell inside the end effector and continues running fast forward until the specified run fast force target is achieved. There are four main faults that can occur during this run fast part of the sequence.
Slow Run Faults 1.Fault #2, Tool Removed During Cycle. If the release ring is pulled during the fast run portion of the cycle, the force being measured by the load cell will drop suddenly and the prox switch will go open. If these two condition are occur then this fault is set. 2.Fault #32, Final Tension Too High. This occurs it the final tension is higher than is allowed in the parameter screen. 3.Fault #33, Final Tension Too Low. This occurs if the final tension is lower than is allowed in the parameter screen. Once the fast run portion of the sequence is completed the slow run portion is executed. In this section of the sequence there are three main Faults that can occur.
Reverse Revolution Faults 1.Fault #2, Tool Removed During Cycle. If the release ring is pulled during the fast run portion of the cycle, the force being measured by the load cell will drop suddenly and the prox switch will go open. If these two condition are occur then this fault is set. 2.Fault #20, Reverse Revolutions not Complete. If the nut runner controller sets the job complete NOK bit then this indicated the number of reverse revolution that were run were not correct. If the PLC gets this signal from the nut runner then if will set his fault. 3.Fault #5, Reverse Revolutions Time Out. Once the reverse revolution run command is sent to the nut runner controller it has 10 sec to send back a job complete Ok or NOK signal. If the PLC does not get either of these within the 10 sec time then this fault is set. Once the slow run portion of the sequence is completed the reverse revolutions portion is executed. In this section of the sequence there are three main Faults that can occur.