Step Monitors

The step monitors are used to verify that the tightening was achieved according to the specification, for example, angle limits or torque. Each step has mandatory step monitors and optional step monitors. The mandatory monitors are included when dragging a new step to the multistep program. The optional monitors are flexible and can be placed as needed in the multistep program. Every step can have up to eight monitors each.

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

Default step monitors

Step Monitor

Applicable steps

Angle

All

Peak Torque

All

A – Angle

This step monitor measures the maximum angle reached during the monitor and checks that it is between High limit and Low limit. The angle measurement starts at the start of the monitor or, if specified, at the point where the torque passes Trigger torque for the first time during the monitor.

Parameter

Description

Type

Four angle types are available: Peak angle (default), Angle at peak torque, Shut off angle, and Angle at end.

Trigger torque

The angle measurement starts at this trigger.

Low Limit

Lowest acceptable angle.

High Limit

Highest acceptable angle.

YA – Angle from Yield

This monitor measures the peak angle reached from the yield point and checks that the peak angle is within the limit.

This step monitor is not available for the STB tools.

Parameter

Description

Gradient Angle Window

Specifies Angle Window:

  • For Hard Joint: Angle Window = 1 deg.

  • For Soft Joint: Angle Window = 20 deg.

  • Manual: Manually set Angle Window.

Angle Window

Available when Gradient Angle Window is set to Manual. Must be > 0 and <= 100.

Yield Point Percentage

Must be >= 20 %

Trigger Torque

The angle measurement starts at this trigger. Must be > 0 and < Tool MaxTorque.

Damping

Frequency in which the gradient is being calculated. Must be > 0 and < 100 and < Angle window.

Low Limit

Lowest acceptable angle. Must be >= 0

High Limit

Highest acceptable angle. Must be > 0

Torque Filter Type

The type of the filter:

  • None: No filtering of the torque is used. The raw values are used as-is in the gradient calculation.

  • Five-point: The torque value used in the calculation are filtered using a sliding average filter over 5 torque samples.

  • Low pass: The torque values is filtered with a simple discrete Infinite Impulse Response filter.

  • Sliding Average: The torque values used in the calculation are filtered using a sliding average filter over a Number of Samples specified by the use.

Cut-off Frequency

Needs to be specified when Torque Filter Type is set to Low pass:

  • 20 Hz

  • 40 Hz

  • 90 Hz

  • 200 Hz

  • 600 Hz

Number of Samples

Needs to be specified when Torque Filter Type is set to Sliding Average:

  • 2

  • 4

  • 6

  • 8

  • 16

  • 32

MT – Mean Torque

This monitor measures the average torque during the monitor and checks the calculated value is within the limits.

This step monitor is not available for the STB tools.

Parameter

Description

Type

Specifies start condition:

  • Step Start: The measurement starts from step start and ends at the shut-off point.

  • Torque Trigger: The measurement starts at the point where the torque passes Torque Trigger for the first time. It ends at the shut-off point.

  • Angle Trigger: The measurement starts at the point where the angle is Angle Trigger, measured from the optional Trigger Torque, is reached. Without Trigger Torque, the Angle Trigger is measured from the start of the step. It ends at the shut-off point

  • Angle Window: Measures during an Angle Window. The window starts at the point where the torque passes Trigger Torque for the first time plus an angle offset, Angle Trigger.

  • Time Interval: Measures during the last Time Interval seconds of the tightening.

Torque Trigger

Available when Type is set to Trigger Torque, Angle Trigger or Angle Window. Must be >= 0 and < Tool Max Torque.

Angle Trigger

Available when Type is set to Angle Trigger or Angle Window. Must be > 0.

Angle Window

Available when Type is set to Angle Window. Must be > 0.

 

Time Interval

Available when Type is set to Time Interval. Must be > 0.

Low Limit

Lowest acceptable torque.

High Limit

Highest acceptable torque.

PT – Peak Torque

This step monitor measures the maximum torque reached during the monitor, including any over shoot, and checks that it is between High limit and Low limit.

Parameter

Description

Low Limit

Lowest acceptable torque.

High Limit

Highest acceptable torque.

PTCA – Post Thread Cut Angle

Measures the angle achieved during the monitoring and checks that it is between the specified angle limits. The Trigger Torque level is ignored until the end of the Thread cut angle window is reached. After that, the angle measuring starts as soon as the measured torque is above Trigger Torque. The parameter Stop Condition specifies where the angle measurement should end.

Parameter

Description

Trigger torque

Must be >= 0

Thread cutting angle window

Must be > 0

Angle measurement type

Peak angle

Angle at peak torque

Shut off angle

Angle at end

Thread cut trigger torque

Must be >= 0

Low Limit

Must be >= 0

High Limit

Must be > 0

Must be > Low limit

PTCPT – Post Thread Cut Peak Torque

Measures the maximum torque achieved during the monitoring, including any over-shoot, and checks that it is between the Torque limits. All torque values are ignored until the end of the Thread cut angle window has been reached.

Parameter

Description

Thread cut trigger torque

Must be >= 0

Thread cutting angle window

Must be > 0

Low Limit

Must be >= 0

High Limit

Must be > 0

Must be > Low limit

PVTH – Post View Torque High

This monitor checks that all torque values in the Angle Window Length are below the High limit.

The Angle Window starts at the angle degrees set in Start Angle in reverse direction from the shut-off point. This then spans for the angle degrees set in Angle Window Length in reverse direction. If Start Angle is left blank, the Angle Window starts at the shut-off point. The torque values used in the monitor are based on the mean torque value, calculated over Number of Samples. If the total angle of the step is less than Start Angle plus Angle Window Length the monitor will report NOK.

Parameter

Description

Start Angle

Must be >= 0

Window length

Must be > 0

Number of samples

Minimum value =1
Maximum value = 80

High Limit

Highest acceptable torque.

PVTL – Post View Torque Low

Same as monitor Post View Torque High, but this monitor checks that all torque values in the Angle Window Length are above Low Limit instead.

Parameter

Description

Start Angle

Must be >= 0

Window length

Must be > 0

Number of samples

Minimum value =1
Maximum value = 80

Low Limit

Lowest acceptable torque.

PrT – Prevailing Torque

The monitor calculates the prevailing torque value in the Window Length and checks that it is between the Torque limits. The Angle Window starts at the angle degrees set in Start Angle in reverse direction from the shut-off point. This then spans for the angle degrees set in Angle Window Length in reverse direction. If Start Angle is left blank the angle window starts at the shut-off point. The calculated prevailing torque value is the mean or peak torque value (depending on the parameter set by the user) during the Window Length. The calculated value is saved as result data Prevailing Torque Measured. If Torque compensation is set to On, the Prevailing Torque Measured will be subtracted from all torque result values in consecutive steps. Any previously calculated prevailing torque compensation values will no longer be subtracted from torque result values. If Torque compensation is set to No, no subtraction will be made in consecutive steps.

If the total angle of the step is less than the Start Angle plus Window Length, then the monitor will report NOK.

Prevailing torque can be measured as an average of measured values, or at peak torque. To choose between these two modes, set the Use Value parameter to either Mean torque (for average values), or Peak torque (for peak value).

Parameter

Description

Torque Compensation

On or off.

Start Angle

Must be > 0

Window length

Must be >= 0

Low Limit

Must be > 0

High Limit

Must be >= 0

Use value

Mean torque (for average values), or Peak torque (for peak value).

SOT – Shut Off Torque

The shut off point is the point where the step reaches its target. The torque is measured at the shut off point and checked to be between High limit and Low limit.

Parameter

Description

Low Limit

Lowest acceptable torque.

High Limit

Highest acceptable torque.

SOC – Shut Off Current

The shut off point is the point where the step reaches its target. The current is measured at the shut off point and checked to be between High limit and Low limit .

Parameter

Description

Low Limit

Lowest acceptable current.

High Limit

Highest acceptable current.

SSD - Stick Slip Detection

This step monitor detects and reports stick slip effects during a step. The detection is done by counting the number of times the torque falls below the Trigger Level. If the number of times is larger than Maximum Number of Oscillations then the stick slip error is reported. The monitor operates in two different modes, Dynamic or Fixed. The difference between the modes is the way that the Trigger level is calculated.

Dynamic Torque: Trigger Level is dynamically calculated as Peak Torque Percentage of the current max torque, which has been achieved so far during the monitoring. The monitoring is started as soon as the torque passes the Trigger Torque.

Fixed Torque: Trigger Level is the fixed Trigger Torque specified by the user. In this mode the percentage is not needed.

If the torque never reaches the Trigger Torque then the monitoring is not started, this will result in status NOK.

Parameter

Description

Type

Specifies what type of Stick slip detection that will be done in the monitor Stick Slip detection. Default: Dynamic torque.

Peak Torque Percentage

Default: 80%, Must be >=10 and < 100.

Trigger Torque

Default: 5, Must be >= 0 and < Tool max torque.

Maximum Number of Oscillations

Default: 5, Must be >= 3 and <20.

Ti – Time

Measures the elapsed time during the monitor and checks that it is between the time limits. The time measurement starts at the start of the monitor and, if the Trigger Torque is specified, at the point where the torque passes Trigger Torque for the first time during the monitor.

Parameter

Description

Trigger Torque

Must be >= 0 and < Tool max torque.

Low Limit

Must be >= 0

High Limit

Must be > 0

Must be > Low limit

TG – Torque Gradient

This monitor checks the gradient is within the limit.

Parameter

Description

Gradient Angle Window

Specifies Angle Window:

  • For Hard Joint: Angle Window = 1 deg.

  • For Soft Joint: Angle Window = 20 deg.

  • Manual: Manually set Angle Window.

Angle Window

Available when Gradient Angle Window is set to Manual. Must be > 0 and <= 100.

End Point Check

If set to Yes, only the gradient measured at the shut off point of the step is checked to be within the limits.

Trigger Torque

The angle measurement starts at this trigger. Must be > 0 and < Tool MaxTorque.

Damping

Frequency in which the gradient is being calculated. Must be > 0 and < 100 and < Angle window.

Low Limit

Lowest acceptable torque gradient. Must be >= -100.

High Limit

Highest acceptable torque gradient. Must be > -100 and > Low limit.

Torque Filter Type

The type of the filter:

  • None: No filtering of the torque is used. The raw values are used as-is in the gradient calculation.

  • Five-point: The torque value used in the calculation are filtered using a sliding average filter over 5 torque samples.

  • Low pass: The torque values is filtered with a simple discrete Infinite Impulse Response filter.

  • Sliding Average: The torque values used in the calculation are filtered using a sliding average filter over a Number of Samples specified by the use.

Cut-off Frequency

Needs to be specified when Torque Filter Type is set to Low pass:

  • 20 Hz

  • 40 Hz

  • 90 Hz

  • 200 Hz

  • 600 Hz

Number of Samples

Needs to be specified when Torque Filter Type is set to Sliding Average:

  • 2

  • 4

  • 6

  • 8

  • 16

  • 32

Angle Offset

Available when End Point Check is set to No. Specifies the degrees that the calculation of the gradient start after the trigger torque is passed for the first time.

TAW – Torque in Angle Window

This monitor checks that all torque values in the angle window are within the torque limits.

Parameter

Description

Trigger Torque

Must be >= 0

Start Angle

Must be > 0

Window Length

Must be <= 0

Low Limit

Must be >= 0

High Limit

Must be > 0

Must be > Low limit

NOK if window is passed

If set to Yes, status of this monitor is NOK if the end of angle window is not reached.

TRD – Torque Rate and Deviation

This step monitor measures and checks the torque rate, i.e. the ratio of torque vs. angle. The calculated torque rate is checked if it is within the torque rate limits defined by High Limit and Low Limit.

Parameter

Description

Trigger Torque

Torque of the angle start point.

Start Point Angle

When Start point angle has been measured from Trigger torque the measuring of the torque starts.

End Point Angle

Angle point where the measuring of the torque is stopped.

End Point Torque

Torque where the measuring of the torque is stopped.

Low Limit

Lowest acceptable torque.

High Limit

Highest acceptable torque.

Limit

Must be > 0

Cl – Click

Monitor to enable click torque and click angle results. This monitor has no settings, and can only be used in conjunction with the MWR step.

LD - Loosening Detection

This monitor can be used to check the torque and direction to see if a loosening is attempted when using the Wrench Production step strategy for an STWrench. If the applied torque is above the value set for Loosening Limit in the direction opposite to the configured thread direction of the program, the result shall be reported as NOK.