1. Power Focus 6000
2. Configuration
3. Working with the Tightening Tab
4. Multistep Programs
5. Step Restrictions

Step Restrictions

To make sure the tightening stops if something unexpected happens, it is possible to add step restrictions to the multistep tightening program. These restrictions could, for example, test that a maximum torque is not reached or that a part of the multistep tightening does not take too long to run. Each step has its own set of mandatory step restrictions and optional step restrictions. The mandatory restrictions are included when dragging a new step to the multistep program. All steps can have up to four restrictions each.

In Power Focus 6000 StepSync and Power Focus 8 StepSync controllers, it is possible to use synchronization points in the tightening program. When any condition that is set for a restriction is met, the tool will be stopped immediately and the program jumps to the next synchronization point (only valid for the Power Focus 6000 StepSync, Power Focus 8 StepSync and Flex), or the end of the program. In controllers without StepSync the tool is stopped immediately and the program jumps to the end of the program.

For Flex only:

For each restriction, select Repairable = Yes to allow retry when tightening stops.

The following restrictions are automatically added to every step that is added to the multistep tightening program.

CTh – Cross Thread

This restriction checks the angle from the point where torque passes Start torque (T1) to the point where the torque passes End torque (T2). If the angle measured from Start torque (T1) is higher than Maximum limit (Amax), the tool is stopped immediately.

When the torque passes End torque (T2), the measured angle is checked against the limit Minimum limit (Amin). If the angle is lower than this limit, the tool is stopped immediately.

C – Current

This step restriction is not supported for Power Focus XC.

This restriction checks the actual current where torque passes Torque Trigger. If the actual current exceeds the limits, the tool will be stopped immediately and the tightening program will jump to the next synchronization point or the end of the program. The result will be the first peak or low value, that made the monitor NOK. In case of OK, the result will be the last measured current value. If the torque trigger is never reached during the restriction it will end with status OK.

A – Maximum Angle

This restriction measures the angle. If the measured angle reaches the Maximum Limit, the tool is stopped immediately. The angle is measured from the start of the restriction or, if specified, from the point where the torque passes Trigger Torque for the first time during the restriction.

T – Maximum Torque

This restriction checks the torque. If the measured torque exceeds the Maximum limit, the tool is stopped immediately.

Ti – Maximum Time

This restriction checks the time. If Maximum Limit is reached, the tool is stopped immediately.

RH – Rehit

This restriction checks the torque. If the measured torque exceeds the Detection Torque, the tool is stopped immediately and the program jumps to the next synchronization point (for Power Focus 6000 StepSync and Power Focus 8 StepSync), or the end of the program.

It is only possible to add step Rehit restriction to the first step of the multistep tightening program. Once the Rehit restriction has been added to the first step it shall not be possible to move the step to any other position within the tightening program. The Rehit restriction has to be deleted from the first step in order to move it to other position in the tightening program.

RT – Rescinding Torque

This restriction checks the torque. If the measured torque drops below the condition of the restriction the tool is stopped immediately and the program jumps to the next synchronization point (for Power Focus 6000 StepSync and Power Focus 8 StepSync), or the end of the program.

• Torque control processes
  The restriction condition is the measured torque. For the restriction to be active the torque must first exceed 110 % of the Rescinding Torque Limit.

• Angle control processes
  This restriction checks the maximum torque reached during the restriction. For the restriction to be active the torque must first exceed the Trigger Torque.

Cable tools have the option to select Rescinding Torque for Angle. This restriction is controlled by two parameters: Peak Torque Percentage and Rescending Torque Time. Percentage sets the downward deviation from the last peak torque, and Rescending Torque Time sets the duration (between 5 and 500 ms) of that deviation. Only when both conditions (equal to or lower than the indicated percentage for the set duration) are met, will the program be interrupted and jump to the end.

TG – Torque Gradient

This restriction checks the gradient and if it is outside the limits the tool is stopped immediately and the program jumps to the end of the program.

TAW – Torque in Angle Window

This restriction checks that the measured torque in the Angle Window Length is between the Torque limits. If the measured torque is outside the limits the tool is stopped immediately and the program jumps to the end. The Angle Window Length starts at the Start Angle from the point that the torque first passed the Trigger Torque. If Trigger Torque is not set, then the Start Angle begins at the start of the restriction.

If the end of the Angle Window Length is not reached, the status of the restriction is NOK.

TCD - Torque vs Current Deviation

This restriction verifies that all current measurements converted to the corresponding torque are, at most, the Maximum deviation away from the actual torque measured with the torque transducer. The restriction starts when the torque reaches Trigger Torque for the first time during the step and is active until the step reaches its target.

If Trigger Torque is never reached, the monitor will report OK.

PCH - Pulse Count High

This restriction is only available for the following tools:

• ETV-STR61-100-13

• ETV-STR61-70-13

• ETV-STR61-50-10

Before using the Pulse Count restriction, the Low Reaction Strategies license must be installed on the controller.

This restriction gives a limit to the number of pulses, and makes sure that those are below the specified pulse count high limit.
If the measured number of pulses is higher than the pulse count high limit, the tool is stopped immediately and the program goes to the next synchronization point or the end of the program.
If the torque trigger level is set, the check starts as soon as the measured torque is above the torque trigger level.

If running a tightening step with Pulse Count High step restriction, use the necessary PulseDrive socket/adapter.
If the tightening step runs without the PulseDrive socket/adapter, all the tightenings are NOK. The step error “PulseDrive socket/adapter not detected” shows for no PulseDrive socket/adapter.