Step Restrictions

To make sure the tightening stops if something unexpected happens, it is possible to add restrictions to the multistep tightening program. For each restriction, select Repairable = Yes to allow retry when tightening stops. For each of the steps in a multistep program it is possible to have up to four restrictions.

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 and the program jumps to the next synchronization point.

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 and the program jumps to the next synchronization point.

Parameter

Description

In illustration

Start torque

Must be <=0.

T1

End torque

Must be <=0.

T2

Minimum limit

The low angle limit.

Amin

Maximum limit

The high angle limit.

Amax

A – Maximum Angle

This restriction measures the angle. If the measured angle reaches the Maximum limit, the tool is stopped immediately and the program jumps to the next synchronization point. 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.

Parameter

Description

Trigger torque

If specified, this is the torque from where the angle is measured.

Maximum limit

If this limit is reached the tool is stopped immediately and the program jumps to the next synchronization point.

T – Maximum Torque

This restriction checks the torque. If the measured torque exceeds the Maximum limit, the tool is stopped immediately and the program jumps to the next synchronization point.

Parameter

Description

Maximum limit

If the torque reaches this specified limit the tool is stopped immediately and the program jumps to the next synchronization point

RH – Rehit

This restriction checks the torque. If the measured torque exceeds the Torque Limit, the tool is stopped immediately and the program jumps to the next synchronization point, or the end of the program.

Parameter

Description

Torque Limit

If the torque reaches this specified limit the tool is stopped immediately and the program jumps to the next synchronization point, or the end of the program.

RT – Rescinding Torque

This restriction checks the torque. If the measured torque is lower than the limit Torque low limit, the tool is stopped immediately and the program jumps to the next synchronization point, or the end of the program.

Parameter

Description

Rescinding torque limit

Default: 10 Nm. Must be > 0.

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 next synchronization point or the end of the program.

Parameter

Description

Gradient Angle Window

Specifies Angle Window:

  • For Hard Joint: Angle Window = 20.

  • For Soft Joint: Angle Window = 1.

  • Manual: Manually set Angle Window.

Angle Window

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

Trigger Torque

Must be > 0 and < Tool MaxTorque.

Damping

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

Minimum Limit

Must be >= -100.

Maximum Limit

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

TAW – Torque in Angle Window

This restriction checks that the measured torque in the angle window is within its limits. If the measured torque is outside the limits the tool is stopped immediately and the program jumps to the next synchronization point, or the end of the program.

Parameter

Description

Trigger torque

Must be >= 0

Start angle

Must be >= 0

Window length

Must be >0

Minimum limit

Must be >= 0

Maximum limit

Must be <= Minimum limit

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.

Parameter

Description

Trigger torque

Must be >= 0

Maximum deviation

Default: 1, Must be > 0

PCH - Pulse Count High

Before using Pulse Count High step restriction, it is mandatory that the following license type is installed on the controller:

  • Low Reaction Strategies

Pulse Count High is valid only for the following tools: ETV-STR61-100-13, ETV-STR61-70-13, ETV-STR61-50-10.

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.

Parameter

Description

Pulse Count High Limit - n+

Pulse count high limit must range from 1 through 9999999.
Pulse Count High Limit text box can be empty.

Torque Trigger - Tt

Torque Trigger must range from 0 through the maximum torque of the tool.
Torque Trigger text box can be empty.