Menu 12 − User Functions 2 and Brake Control

Mode: Open‑Loop

Menu 12 provides parameters for the following features:

  1. Threshold detectors
  2. Variable selectors
  3. Mechanical brake controller


Parameter12.001  Threshold Detector 1 Output
Short descriptionDisplays the output of threshold detector 1
ModeOpen‑Loop
Minimum0Maximum1
Default Units 
Type1 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places0
CodingRO, ND, NC, PT

The threshold detector functions are always active even if the source and destination are not routed to valid parameters. If the source is not a valid parameter then the source value is taken as 0. The update rate for each of the threshold detector functions is always 4ms.

The following description is for threshold detector 1, but threshold detector 2 operates in the same way. The level of the parameter defined by Threshold Detector 1 Source (12.003) is converted to a percentage and compared to Threshold Detector 1 Level (12.004) with hysteresis to give Threshold Detector 1 Output (12.001) as follows:

Source Threshold Detector 1 Output (12.001)
Source 0
Lower threshold ≤ Source No change of state
Source ≥ Upper threshold 1

Lower threshold = Threshold Detector 1 Level (12.004)Threshold Detector 1 Hysteresis (12.005)
Upper threshold = Threshold Detector 1 Level (12.004) + Threshold Detector 1 Hysteresis (12.005)

The output value can then be inverted with Threshold Detector 1 Output Invert (12.006) before being routed to the destination defined by Threshold Detector 1 Destination (12.007).


Parameter12.002  Threshold Detector 2 Output
Short descriptionDisplays the output of threshold detector 1
ModeOpen‑Loop
Minimum0Maximum1
Default Units 
Type1 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places0
CodingRO, ND, NC, PT

See Threshold Detector 1 Output (12.001).


Parameter12.003  Threshold Detector 1 Source
Short descriptionDefines the source paramter for threshold detector 1
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See Threshold Detector 1 Output (12.001).


Parameter12.004  Threshold Detector 1 Level
Short descriptionDefines the reference level for threshold detector 1
ModeOpen‑Loop
Minimum0.00Maximum100.00
Default0.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See Threshold Detector 1 Output (12.001).


Parameter12.005  Threshold Detector 1 Hysteresis
Short descriptionDefines the hysteresis for threshold detector 1
ModeOpen‑Loop
Minimum0.00Maximum25.00
Default0.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See Threshold Detector 1 Output (12.001).


Parameter12.006  Threshold Detector 1 Output Invert
Short descriptionSet to 1 to invert the output of threshold detector 1
ModeOpen‑Loop
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW

See Threshold Detector 1 Output (12.001).


Parameter12.007  Threshold Detector 1 Destination
Short descriptionDefines the destination parameter for threshold detector 1
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, DE, PT, BU

See Threshold Detector 1 Output (12.001).


Parameter12.008  Variable Selector 1 Source 1
Short descriptionDefines the 1st source parameter for variable selector 1
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

The variable selector functions are always active even if the source and destination are not routed to valid parameters. If a source is not a valid parameter then the source value is taken as 0. The update rate for each of the variable selector functions is always 4ms.

The following description is for variable selector 1, but variable selector 2 operates in the same way. The source parameters selected with Variable Selector 1 Source 1 (12.008) and Variable Selector 1 Source 2 (12.009) are converted to a percentage value, scaled with Variable Selector 1 Source 1 Scaling (12.013) and Variable Selector 1 Source 2 Scaling (12.014) respectively and then combined with a function defined by Variable Selector 1 Mode (12.010) to give Variable Selector 1 Output (12.012) as a percentage value. If Variable Selector 1 Enable (12.016) = 1 then the function operates normally. If Variable Selector 1 Enable (12.016) = 0 then Variable Selector 1 Output (12.012) = 0.00% and any states within the function are reset (i.e. the time constant function accumulator is held at zero). If the value of Variable Selector 1 Mode (12.010) is changed then all internal function state are also reset.

The table below shows the functions that can be selected with Variable Selector 1 Mode (12.010).

Variable Selector 1 Mode (12.010) Variable Selector 1 Output (12.012)
0: Input 1 Input 1
1: Input 2 Input 2
2: Add Input 1 + Input 2
3: Subtract Input 1 - Input 2
4: Multiply (Input 1 x Input 2) / 100.00%
5: Divide (Input 1 x 100.00%) / Input 2
6: Time Const Input 1 / (1 + τs) where τ = Variable Selector 1 Control (12.015) seconds
7: Ramp Input 1 as an input to a linear ramp function where the time to ramp from 0.00% to 100.00% is defined by Variable Selector 1 Control (12.015) seconds
8: Modulus |Input1|
9: Powers

If Variable Selector 1 Control (12.015) = 0.02 then Input2 / 100.00%

Else if Variable Selector 1 Control (12.015) = 0.03 then Input3 / 100.00%

Else Input 1

10: Sectional See description below

Sectional Controller

If Variable Selector 1 Mode (12.010) = 10 then the variable selector can be used to provide a sectional control function. (Variable selector 2 operates in the same way.) The sectional control function is intended to apply scaling and a speed offset to a 16 bit position value to generate a new 16 bit position value. The output can be used as an input to the Standard motion controller (Menu 13) and to generate an encoder simulation output (Menu 3).

The position input is selected with Variable Selector 1 Source 1 (12.008) and can be derived from any parameter. However, it is intended to be used with a position value that has a range from 0 to 65535 (e.g. P1 Position (03.029)). The input is scaled so that as Variable Selector 1 Source 1 Scaling (12.013) is changed between -4.000 and 4.000 so the proportion of the input position change added to the accumulator varies from 0.000 to 2.000 (i.e. the change of position input value is added without scaling if Variable Selector 1 Source 1 Scaling (12.013) = 0.000). The remainder from the scaling division is stored and then added at the next sample to maintain an exact ratio between the position input and the position output, provided the speed from source 2 is zero. The controller only takes the change of position from the input source parameter, and not the absolute value, so that when the controller is first made active the output does not jump to the source position, but only moves with any changes of source position after that point in time.

The range of Variable Selector 1 Output (12.012) is 0.00% and 100.00%. Unlike other functions the value is not simply limited, but rolls under or over respectively. Although the output destination can be any parameter it is intended to be used with a position value that has a range from 0 to 65535.

The speed input defines a speed offset with a resolution of 0.1rpm. Full scale of the source parameter corresponds to 1000.0rpm. Scaling may be applied using Variable Selector 1 Source 2 Scaling (12.014) to give a full scale value up to 4000.0rpm. The speed input is added to the accumulator to move the output position forwards or backwards with respect to the position input.

The sample time for the variable selector is 4ms and the input or output position must not change by more than half a revolution over this time. Therefore the input or output speed must not exceed 7500rpm.

The diagram below shows an example of how the sectional controller function could be configured. The section input position is provided from the previous section via the P1 position feedback interface. The destination of the variable selector is the Standard Motion Local Reference Position (13.021) in the standard motion controller which is used to provide the speed reference and to control the local motor attached to the drive. The encoder simulation system is used to generate the section output to be fed into the next drive. The source for the encoder simulation is Standard Motion Local Reference Position (13.021).


Parameter12.009  Variable Selector 1 Source 2
Short descriptionDefines the 2nd source parameter for variable selector 1
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See Variable Selector 1 Source 1 (12.008).


Parameter12.010  Variable Selector 1 Mode
Short descriptionDefines the mode for variable selector 1
ModeOpen‑Loop
Minimum0Maximum10
Default0Units 
Type8 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places0
CodingRW, TE

ValueText
0Input 1
1Input 2
2Add
3Subtract
4Multiply
5Divide
6Time Const
7 Ramp
8Modulus
9Powers
10Sectional

See Variable Selector 1 Source 1 (12.008).


Parameter12.011  Variable Selector 1 Destination
Short descriptionDefines the destination parameter for variable selector 1
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, DE, PT, BU

See Variable Selector 1 Source 1 (12.008).


Parameter12.012  Variable Selector 1 Output
Short descriptionDisplays the output of variable selector 1
ModeOpen‑Loop
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places2
CodingRO, ND, NC, PT

See Variable Selector 1 Source 1 (12.008).


Parameter12.013  Variable Selector 1 Source 1 Scaling
Short descriptionDefines the scaling for the 1st input for variable selector 1
ModeOpen‑Loop
Minimum-4.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places3
CodingRW

See Variable Selector 1 Source 1 (12.008).


Parameter12.014  Variable Selector 1 Source 2 Scaling
Short descriptionDefines the scaling for the 2nd input for variable selector 1
ModeOpen‑Loop
Minimum-4.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places3
CodingRW

See Variable Selector 1 Source 1 (12.008).


Parameter12.015  Variable Selector 1 Control
Short descriptionDefines the control for variable selector 1
ModeOpen‑Loop
Minimum0.00Maximum100.00
Default0.00Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See Variable Selector 1 Source 1 (12.008).


Parameter12.016  Variable Selector 1 Enable
Short descriptionEnables variable selector 1
ModeOpen‑Loop
Minimum0Maximum1
Default1Units 
Type1 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW, BU

See Variable Selector 1 Source 1 (12.008) for more details.

Variable Selector 1 Enable (12.016) and Variable Selector 2 Enable (12.036) have a default of 1 so that if these parameters are not used the variable selectors will still function.


Parameter12.023  Threshold Detector 2 Source
Short descriptionDefines the source paramter for threshold detector 2
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See Threshold Detector 1 Output (12.001).


Parameter12.024  Threshold Detector 2 Level
Short descriptionDefines the reference level for threshold detector 2
ModeOpen‑Loop
Minimum0.00Maximum100.00
Default0.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See Threshold Detector 1 Output (12.001).


Parameter12.025  Threshold Detector 2 Hysteresis
Short descriptionDefines the hysteresis for threshold detector 2
ModeOpen‑Loop
Minimum0.00Maximum25.00
Default0.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See Threshold Detector 1 Output (12.001).


Parameter12.026  Threshold Detector 2 Output Invert
Short descriptionSet to 1 to invert the output of threshold detector 2
ModeOpen‑Loop
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW

See Threshold Detector 1 Output (12.001).


Parameter12.027  Threshold Detector 2 Destination
Short descriptionDefines the destination parameter for threshold detector 2
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, DE, PT, BU

See Threshold Detector 1 Output (12.001).


Parameter12.028  Variable Selector 2 Source 1
Short descriptionDefines the 1st source parameter for variable selector 2
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See Variable Selector 1 Source 1 (12.008).


Parameter12.029  Variable Selector 2 Source 2
Short descriptionDefines the 2nd source parameter for variable selector 2
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See Variable Selector 1 Source 1 (12.008).


Parameter12.030  Variable Selector 2 Mode
Short descriptionDefines the mode for variable selector 2
ModeOpen‑Loop
Minimum0Maximum10
Default0Units 
Type8 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places0
CodingRW, TE

ValueText
0Input 1
1Input 2
2Add
3Subtract
4Multiply
5Divide
6Time Const
7 Ramp
8Modulus
9Powers
10Sectional

See Variable Selector 1 Source 1 (12.008).


Parameter12.031  Variable Selector 2 Destination
Short descriptionDefines the destination parameter for variable selector 2
ModeOpen‑Loop
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, DE, PT, BU

See Variable Selector 1 Source 1 (12.008).


Parameter12.032  Variable Selector 2 Output
Short descriptionDisplays the output of variable selector 2
ModeOpen‑Loop
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places2
CodingRO, ND, NC, PT

See Variable Selector 1 Source 1 (12.008).


Parameter12.033  Variable Selector 2 Source 1 Scaling
Short descriptionDefines the scaling for the 1st input for variable selector 2
ModeOpen‑Loop
Minimum-4.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places3
CodingRW

See Variable Selector 1 Source 1 (12.008).


Parameter12.034  Variable Selector 2 Source 2 Scaling
Short descriptionDefines the scaling for the 2nd input for variable selector 2
ModeOpen‑Loop
Minimum-4.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places3
CodingRW


Parameter12.035  Variable Selector 2 Control
Short descriptionDefines the control for variable selector 2
ModeOpen‑Loop
Minimum0.00Maximum100.00
Default0.00Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See Variable Selector 1 Source 1 (12.008).


Parameter12.036  Variable Selector 2 Enable
Short descriptionEnables variable selector 2
ModeOpen‑Loop
Minimum0Maximum1
Default1Units 
Type1 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW, BU

See Variable Selector 1 Source 1 (12.008).


Parameter12.040  Brake Control: Brake Release
Short descriptionEnables the brake release function
ModeOpen‑Loop
Minimum0Maximum1
Default Units 
Type1 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places0
CodingRO, ND, NC, PT

The mechanical brake control function can be used to control an electro-mechanical brake via digital I/O. Brake Control: Brake Release (12.040) = 0 when the brake should be applied and 1 when the brake should be released. Normally this should be routed to a digital output to control the mechanical brake. See Brake Control: Enable (12.041) for details.


Parameter12.041  Brake Control: Enable
Short descriptionEnables the brake control function
ModeOpen‑Loop
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places0
CodingRW

If Brake Control: Enable (12.041) = 0 then the brake controller is disabled. The following parameters which are used by the brake controller to operate the drive are reset to 0 on the transition of Brake Control: Enable (12.041) from 1 to 0.

Parameter
Force Reference Direction (01.057)
Ramp Hold (02.003)

Open-loop mode

Current detection
The Current Magnitude (04.001) is compared to an upper and lower threshold by a comparator with hysteresis to give torque present and drive output open detection functions respectively. Brake Control: Lower Current Threshold (12.043) and Brake Control: Upper Current Threshold (12.042) are given as a percentage of Rated Current (05.007). Brake Control: Upper Current Threshold (12.042) should be set to the current level that indicates that there is magnetising current and sufficient torque producing current in the motor to deliver the required amount of torque when the brake is released. The output of the comparator remains active after this level has been reached unless the current subsequently falls below Brake Control: Lower Current Threshold (12.043) which should be set to the required level to detect the condition where the motor has been disconnected from the drive. If Brake Control: Lower Current Threshold (12.043)Brake Control: Upper Current Threshold (12.042) then the upper threshold applies with a hysteresis band of 0. If Brake Control: Lower Current Threshold (12.043) = Brake Control: Upper Current Threshold (12.042) = 0 then the output of the comparator is always one.

Frequency detection
The frequency comparator is used on starting, to detect when the motor frequency has reached a level where the motor can produce the required amount of torque to ensure that the motor rotates in the demanded direction when the brake is released. Brake Control: Brake Release Frequency (12.044) should be set to a level slightly above the motor slip frequency that is likely to occur under the highest expected load that is applied to the motor when the brake is released.

The brake apply frequency threshold is used to ensure that the brake is applied before the motor frequency reaches zero and to prevent the motor rotating (in the reverse direction due to an overhauling load for example) during the brake apply time. If the frequency falls below Brake Control: Brake Apply Frequency (12.045), but the motor is not required to stop (i.e. reversing direction without stopping) then Reference On (01.011) will be one, and so the brake is not applied. This prevents the brake from activating and de-activating as the motor passes through zero speed. If the frequency falls below Brake Control: Brake Apply Frequency (12.045) and Reference On (01.011) = 0 then the brake will be applied.

Brake controller sequence
The brake controller sequence is shown for forward movement in the diagram below.

The current detection, frequency detection and Drive Active (10.002) levels are used to allow the brake to be released. Brake Control: Brake Delay (12.046) is the delay allowed after the correct current and frequency levels have been detected before the brake is released. Brake Control: Post-brake Release Delay (12.047) is the time allowed for the brake to be released before the frequency is allowed to increase above the Brake Control: Brake Release Frequency (12.044).

Applying the brake as the frequency passes through zero
In Open-loop mode the torque produced may reduce as the frequency passes through zero. To prevent the load from falling during this period in a vertical application, it is possible to apply the brake momentarily to hold the load. If Brake Control: Brake Apply Through Zero Threshold (12.051) = 0 then the brake is not applied when the frequency passes through zero unless Reference On (01.011) = 0. If Brake Control: Brake Apply Through Zero Threshold (12.051) is non-zero then the brake is always applied when the modulus of frequency is less than Brake Control: Brake Apply Through Zero Threshold (12.051) even if Reference On (01.011) = 1. This ensures that the brake is applied and then released as the frequency passes through zero. Brake Control: Brake Apply Through Zero Threshold (12.051) should be set to a value that is lower than both Brake Control: Brake Release Frequency (12.044) and Brake Control: Brake Apply Frequency (12.045) so that it does not interfere with the control of the brake when starting and stopping. 

Forced initial direction
If Brake Control: Initial Direction (12.050) = 0 then the brake controller operates as described above and the user reference is used to define the direction of operation. If Brake Control: Initial Direction (12.050) = 1 then Force Reference Direction (01.057) is used force the frequency reference to the positive modulus of its value until the end of the post-brake release period whatever the direction of the reference from the user. This can be used for example to ensure that in a vertical application the motor will definitely hold the load at the point when the brake is released. The diagram below shows the brake controller sequence when Brake Control: Initial Direction (12.050) = 1, but the user reference direction is reverse. It should be noted that Brake Control: Initial Direction (12.050) has no effect if Brake Control: Brake Apply Through Zero Threshold (12.051) is non-zero, and that the reference direction is always used as the initial direction, to prevent a condition where the brake would release then apply repeatedly.

If Brake Control: Initial Direction (12.050) = 2 then Force Reference Direction (01.057) is used to force the frequency reference to minus the modulus of its value until the end of the post-brake release period to ensure that the output frequency is negative during this period.

  

 


Parameter12.042  Brake Control: Upper Current Threshold
Short descriptionDefines the upper current threshold for the brake
ModeOpen‑Loop
Minimum0Maximum200
Default50Units%
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW, BU

See Brake Control: Enable (12.041).


Parameter12.043  Brake Control: Lower Current Threshold
Short descriptionDefines the lower current limit for the brake
ModeOpen‑Loop
Minimum0Maximum200
Default10Units%
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW, BU

See Brake Control: Enable (12.041).


Parameter12.044  Brake Control: Brake Release Frequency
Short descriptionDefines the brake release frequency
ModeOpen‑Loop
Minimum0.0Maximum20.0
Default1.0UnitsHz
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places1
CodingRW, BU

See Brake Control: Enable (12.041).


Parameter12.045  Brake Control: Brake Apply Frequency
Short descriptionDefines the brake apply frequency
ModeOpen‑Loop
Minimum0.0Maximum20.0
Default2.0UnitsHz
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places1
CodingRW, BU

See Brake Control: Enable (12.041).


Parameter12.046  Brake Control: Brake Delay
Short descriptionDefines the pre-brake release delay
ModeOpen‑Loop
Minimum0.0Maximum25.0
Default1.0Unitss
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places1
CodingRW, BU

See Brake Control: Enable (12.041).


Parameter12.047  Brake Control: Post-brake Release Delay
Short descriptionDefines the post-brake release delay
ModeOpen‑Loop
Minimum0.0Maximum25.0
Default1.0Unitss
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places1
CodingRW, BU

See Brake Control: Enable (12.041).


Parameter12.050  Brake Control: Initial Direction
Short descriptionDefines the initial direction of the brake
ModeOpen‑Loop
Minimum0Maximum2
Default0Units 
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW, TE

ValueText
0Ref
1Forward
2Reverse

See Brake Control: Enable (12.041).


Parameter12.051  Brake Control: Brake Apply Through Zero Threshold
Short descriptionDefines if the brake is applied through zero threshold
ModeOpen‑Loop
Minimum0.0Maximum20.0
Default1.0UnitsHz
Type8 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places1
CodingRW, BU

See Brake Control: Enable (12.041).