Menu 3 − Frequency and Speed Feedback

Mode: RFC‑A

The drive can operate under Open Loop and RFC modes with respect to frequency and current control and can drive asynchronous machines. The open loop asynchronous control is further broken down into vector and fixed boost modes


Parameter03.001  Final Demand Reference
Short descriptionDisplays the final reference to the frequency controller
ModeRFC‑A
Minimum−VM_FREQMaximumVM_FREQ
Default UnitsHz
Type32 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places2
CodingRO, FI, VM, ND, NC, PT

Open loop mode:
Final Demand Reference (03.001) shows the fundamental drive output frequency from the Post Ramp Reference (02.001) and the Hard Frequency Reference (03.022).

RFC modes:
Final Demand Reference (03.001) shows the reference at the input to the frequency controller, which is the sum of the Post Ramp Reference (02.001) if the ramp output is not disabled and the hard frequency reference (if enabled). If the drive is disabled Final Demand Reference (03.001) shows 0.00.


Parameter03.002  Estimated Frequency
Short descriptionDisplays the frequency feedback selected for the frequency controller
ModeRFC‑A
Minimum−VM_FREQMaximumVM_FREQ
Default UnitsHz
Type32 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places2
CodingRO, FI, VM, ND, NC, PT

Estimated Frequency (03.002) shows the level of the frequency feedback selected for the frequency controller.


Parameter03.003  Frequency Error
Short descriptionDisplays the error between the final frequency demand and the estimated frequency
ModeRFC‑A
Minimum−VM_FREQMaximumVM_FREQ
Default UnitsHz
Type32 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places2
CodingRO, FI, VM, ND, NC, PT

RFC modes only. Will be set to zero in open loop modes.

The frequency error is the difference between the final frequency demand and the estimated frequency and does not include the effect of the differential term in the frequency controller feedback branch.


Parameter03.004  Frequency Controller Output
Short descriptionDisplays the output of the frequency controller
ModeRFC‑A
Minimum−VM_TORQUE_CURRENTMaximumVM_TORQUE_CURRENT
Default Units%
Type16 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places1
CodingRO, FI, VM, ND, NC, PT

RFC modes only. Will be set to zero in open loop modes.

The output of the frequency regulator is a torque demand given as a percentage of rated motor torque. It should be noted that this will be modified to take into account the level of motor flux if field weakening is active before it is converted into the Final Current Reference (04.004).


Parameter03.005  Zero Frequency Threshold
Short descriptionDefines the threshold for detecting the zero frequency condition
ModeRFC‑A
Minimum0.00Maximum20.00
Default2.00UnitsHz
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW, BU

If the Post Ramp Reference (02.001) is at or below the level defined by this parameter in either direction Zero Frequency (10.003) = 1, otherwise Zero Frequency (10.003) = 0.


Parameter03.006  At Frequency Lower Limit
Short descriptionDefines the lower limit for detecting the at frequency condition
ModeRFC‑A
Minimum0.00Maximum550.00
Default1.00UnitsHz
Type32 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

At Frequency  (10.006) is set if the Estimated Frequency (03.002) is on the boundaries or within the at speed window. Above Set Frequency  (10.007) and Below Set Frequency (10.005) are set if the feedback is above or below the window respectively.

If Absolute At Frequency Select (03.009) = 0 reference window mode is used.
The "at speed" condition is true if,

(|Pre-ramp Reference (01.003)| - At Frequency Lower Limit (03.006)) ≤ |Estimated Frequency (03.002)| ≤ (|Pre-ramp Reference (01.003)| + At Frequency Upper Limit (03.007))

(If the lower limit is less than zero then zero is used as the lower limit.)

If Absolute At Frequency Select (03.009) = 1 absolute window mode is used.
The "at speed" condition is true if,

At Frequency Lower Limit (03.006) ≤ |Estimated Frequency (03.002)| ≤ At Frequency Upper Limit (03.007)

Note: All flags are cleared if Reference On (01.011) is 0.


Parameter03.007  At Frequency Upper Limit
Short descriptionDefines the upper limit for detecting the at frequency condition
ModeRFC‑A
Minimum0.00Maximum550.00
Default1.00UnitsHz
Type32 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

See At Frequency Lower Limit (03.006).


Parameter03.008  Over Frequency Threshold
Short descriptionDefines the threshold used to detect the over frequency condition
ModeRFC‑A
Minimum0.00Maximum550.00
Default0.00UnitsHz
Type32 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

If Over Frequency Threshold (03.008) is set to a non-zero value it defines the over frequency threshold. If the Estimated Frequency (03.002) exceeds this threshold in either direction an Over Speed trip is produced. If Over Frequency Threshold (03.008) is set to 0.0 the threshold is based on the variable minimum/maximum for the references and is equal to 1.2 x VM_SPEED_FREQ_REF[MAX].


Parameter03.009  Absolute At Frequency Select
Short descriptionSet to 1 to select absolute at frequency
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places0
CodingRW

See At Frequency Lower Limit (03.006).


Parameter03.010  Frequency Controller Proportional Gain Kp1
Short descriptionDefines the proportional gain for frequency controller 1
ModeRFC‑A
Minimum0.000Maximum200.000
Default0.100Unitss/rad
Type32 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places3
CodingRW

RFC modes only.

The diagram below shows a generalised representation of the frequency controller. The controller includes a feed forward proportional gain (Kp), a feed forward integral gain (Ki), and a differential feedback gain (Kd).

The drive holds two sets of these gains and either set may be selected for use by the frequency controller with Frequency Controller Gain Select (03.016). If Frequency Controller Gain Select (03.016) = 0, gains Kp1, Ki1 and Kd1 are used, and if Frequency Controller Gain Select (03.016) = 1, gains Kp2, Ki2 and Kd2 are used.

If Frequency Controller Gain Select (03.016) = 2, Kp1 etc are used while the modulus of the frequency demand is less than the value held by Gain Change Threshold (03.017), else Kp2 etc will be used.

If Frequency Controller Gain Select (03.016) is changed when the drive is enabled, the controller output is kept constant by modifying the level of the integral term accumulator so that the transient produced is minimised.

Proportional gain (Kp)
If Kp is non-zero and Ki is zero the controller will only have a proportional term, and there must be a frequency error to produce a torque reference. Therefore as the motor load increases there will be a difference between the reference and actual frequencies. This effect, called regulation, depends on the level of the proportional gain, the higher the gain the smaller the frequency error for a given load. If the proportional gain is too high the closed-loop stability limit may be reached.

Integral gain (Ki)
The integral gain is provided to prevent frequency regulation. The error is accumulated over a period of time and used to produce the necessary torque reference without any frequency error. Increasing the integral gain reduces the time taken for the frequency to reach the correct level and increases the stiffness of the system, i.e. it reduces the positional displacement produced by applying a load torque to the motor. Unfortunately increasing the integral gain also reduces the system damping giving overshoot after a transient. For a given integral gain the damping can be improved by increasing the proportional gain. A compromise must be reached where the system response, stiffness and damping are all adequate for the application. The integral term is implemented in the form of ?(Ki x error), and so the integral gain can be changed when the controller is active without causing large transients on the torque reference.

Differential gain (Kd)
The differential gain is provided in the feedback of the frequency controller to give additional damping. The differential term is implemented in a way that does not introduce excessive noise normally associated with this type of function. Increasing the differential term reduces the overshoot produced by under-damping, however for most applications the proportional and integral gains alone are sufficient.

It should be noted that the differential term is limited internally so that it is ineffective if frequency in Hz x Kd x Ki is greater than 170.

To analyse the performance of the frequency controller it may be represented as an s-domain model as shown below.

Kc' is the conversion between the frequency controller output and the torque producing current reference. A value of unity at the output of the frequency controller gives a torque producing current equal to Kc'. The drive automatically compensates the torque producing current reference for flux variations in field weakening, and so Kc' can be assumed to have a constant value even in field weakening. Kc' = Full Scale Current Kc (11.061) x 0.45.

Kt is the torque constant of the motor (i.e. torque in Nm per amp of torque producing current). For induction motors the value must be calculated from the motor parameters. In RFC-A mode this calculation is performed by the drive and the result is stored in Torque Per Amp (05.032).

L(s) is the transfer function of the load.


Parameter03.011  Frequency Controller Integral Gain Ki1
Short descriptionDefines the integral gain for frequency controller 1
ModeRFC‑A
Minimum0.00Maximum655.35
Default0.10Unitss²/rad
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places2
CodingRW, BU

RFC modes only.

See Frequency Controller Proportional Gain Kp1 (03.010).


Parameter03.012  Frequency Controller Differential Feedback Gain Kd1
Short descriptionDefines the differential gain for frequency controller 1
ModeRFC‑A
Minimum0.00000Maximum0.65535
Default0.00000Units1/rad
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places5
CodingRW, BU

RFC modes only.

See Frequency Controller Proportional Gain Kp1 (03.010).


Parameter03.013  Frequency Controller Proportional Gain Kp2
Short descriptionDefines the proportional gain for frequency controller 2
ModeRFC‑A
Minimum0.000Maximum200.000
Default0.100Unitss/rad
Type32 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places3
CodingRW

RFC modes only.

See Frequency Controller Proportional Gain Kp1 (03.010).


Parameter03.014  Frequency Controller Integral Gain Ki2
Short descriptionDefines the integral gain for frequency controller 2
ModeRFC‑A
Minimum0.00Maximum655.35
Default0.10Unitss²/rad
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places2
CodingRW, BU

RFC modes only.

See Frequency Controller Proportional Gain Kp1 (03.010).


Parameter03.015  Frequency Controller Differential Feedback Gain Kd2
Short descriptionDefines the differential gain for frequency controller 2
ModeRFC‑A
Minimum0.00000Maximum0.65535
Default0.00000Units1/rad
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places5
CodingRW, BU

RFC modes only.

See Frequency Controller Proportional Gain Kp1 (03.010).


Parameter03.016  Frequency Controller Gain Select
Short descriptionDefines which gains are used for the frequency controller
ModeRFC‑A
Minimum0Maximum2
Default0Units 
Type8 Bit User SaveUpdate Rate16ms
Display FormatStandardDecimal Places0
CodingRW

RFC modes only.

See Frequency Controller Proportional Gain Kp1 (03.010).

Value Selection
0 Kp1, Ki1 & Kd1 used
1 Kp2, Ki2 & Kd2 used
2 Automatic gain change at frequency threshold (Gain Change Threshold (03.017))


Parameter03.017  Gain Change Threshold
Short descriptionDefines the threshold that changes between the two sets of gains for the frequency controller
ModeRFC‑A
Minimum0.00Maximum550.00
Default0.00UnitsHz
Type32 Bit User SaveUpdate Rate16ms
Display FormatStandardDecimal Places2
CodingRW

RFC modes only.

See Frequency Controller Proportional Gain Kp1 (03.010).


Parameter03.018  Motor and Load Inertia
Short descriptionDisplays the inertia of the motor and load
ModeRFC‑A
Minimum0.00Maximum1000.00
Default0.00Unitskgm²
Type32 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

The motor and load inertia represents the total inertia driven by the motor. This is used to provide torque feed-forwards during acceleration when required (see Torque Mode Selector (04.011)).

It is possible to measure the inertia as part of the auto-tune process (See Auto-tune (05.012))


Parameter03.022  Hard Frequency Reference
Short descriptionDefines the value of the hard frequency reference
ModeRFC‑A
Minimum−VM_SPEED_FREQ_REFMaximumVM_SPEED_FREQ_REF
Default0.00UnitsHz
Type32 Bit User SaveUpdate Rate4ms
Display FormatStandardDecimal Places2
CodingRW, VM

The Hard Frequency Reference (03.022) is a reference value which does not pass through the ramp system, but is added directly to the Post Ramp Reference (02.001). The Hard Frequency Reference (03.022) is only added when selected by the Hard Frequency Reference Select (03.023) and Reference On (01.011) is active.


Parameter03.023  Hard Frequency Reference Select
Short descriptionSet to 1 to enable the use of the hard frequency reference
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate Rate4ms
Display FormatStandardDecimal Places0
CodingRW

See Hard Frequency Reference (03.022).


Parameter03.029  Position
Short descriptionDisplays the position counter in frequency or encoder mode
ModeRFC‑A
Minimum0Maximum65535
Default Units 
Type16 Bit Power Down SaveUpdate RateBackground
Display FormatStandardDecimal Places0
CodingRO, FI, ND, NC, PT, BU

Indicates the current value of the position counter in Frequency or Encoder mode. Position is reset to 0 if Position Counter Reset (03.032) is 1.


Parameter03.032  Position Counter Reset
Short descriptionSet to 1 to reset the position counter
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit VolatileUpdate RateBackground
Display FormatStandardDecimal Places0
CodingRW, NC

When set, this parameter resets the position parameter (Position (03.029)) and revolution counter Revolution Counter (03.128) to 0.


Parameter03.035  Position Scaling Numerator
Short descriptionDefines the numerator used for scaling the pulse counter
ModeRFC‑A
Minimum0.000Maximum1.000
Default1.000Units 
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places3
CodingRW, BU

Position Scaling Numerator (03.035) and Position Scaling Denominator (03.036) are used to scale the pulse counter down to the required position units. The multiplying factor applied to the counter is defined as:

Position Scaling Numerator (03.035) ÷ Position Scaling Denominator (03.036)


Parameter03.036  Position Scaling Denominator
Short descriptionDefines the denonminator used for scaling the pulse counter
ModeRFC‑A
Minimum0.000Maximum100.000
Default1.000Units 
Type32 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places3
CodingRW

See Position Scaling Numerator (03.035).


Parameter03.037  Frequency Output or PWM Output Scaling
Short descriptionDefines the scaling factor applied to the frequency or PWM output
ModeRFC‑A
Minimum0.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places3
CodingRW, BU

Scale factor applied to the frequency or PWM output.


Parameter03.038  Maximum Output Frequency
Short descriptionDefines the maximum frequency required at the frequency output
ModeRFC‑A
Minimum0Maximum3
Default2UnitskHz
Type8 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places0
CodingRW, TE, BU

ValueTextDescription
0115.1 bit resolution at Fmax
1214.1 bit resolution at Fmax
2512.8 bit resolution at Fmax
31011.8 bit resolution at Fmax

Defines the maximum frequency required at the frequency output. The choice of maximum output frequency depends on the requirement of the output. Due to limitations in the hardware, higher output frequencies do not offer the best resolution at the top end of the frequency range.1, 2, 5, and 10kHz (0 - 3).

Fmax (kHz) Resolution at Fmax
1 10 bit
2 9
5 8
10 7.7


Parameter03.042  Frequency Input High Precision
Short descriptionIncrease the frequency input measuring window
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places0
CodingRW

If Frequency Input High Precision (03.042) = 1 then the frequency input measurement window is doubled. This doubles the accuracy of the frequency input measurment but increase the response time by two.

If Frequency Input High Precision (03.042) = 0 then the frequency input measurement window is similar to Commander SK with better response time.


Parameter03.043  Maximum Reference Frequency
Short descriptionDefines the maximum frequency expected at the frequency input
ModeRFC‑A
Minimum0.00Maximum100.00
Default10.00UnitskHz
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places2
CodingRW

Defines the maximum frequency expected at the frequency input. The time the frequency is measured over is defined by

Measurement Time = 2048 / Maximum reference frequency

With a maximum measurement time of 0.341 seconds.
2048 is used to give the measurement more stability. The output is 10 bits.
Maximum reference frequency of less than 6kHz will have a lower resolution.


Parameter03.044  Frequency Reference Scaling
Short descriptionDefines the scaling factor applied to the frequency reference
ModeRFC‑A
Minimum0.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places3
CodingRW, BU

Scale factor applied to the frequency reference.


Parameter03.045  Frequency Reference
Short descriptionDisplays the frequency reference
ModeRFC‑A
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places2
CodingRO, FI, ND, NC, PT

Indicates the reference input:

Digital input 6/7 mode (08.036) = 1 this is the reference from the frequency input.
Digital input 6/7 mode (08.036) = 2 this is the reference from the encoder AB input.

The reference has a 16ms filter.


Parameter03.047  Two Point Minimum Frequency
Short descriptionDefines the minimum frequency for scaling the frequency input
ModeRFC‑A
Minimum-100.00Maximum100.00
Default-100.00Units%
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

Frequency Reference (03.045) is scaled and limited using:

Parameters above can be selected to limit the range of Frequency Reference (03.045) and also scale it between the minimum and maximum reference.


Parameter03.048  Drive Reference at Minimum Frequency
Short descriptionDefines the drive reference for scaling the frequency input at minimum frequency
ModeRFC‑A
Minimum-100.00Maximum100.00
Default-100.00Units%
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

See Two Point Minimum Frequency (03.047).


Parameter03.049  Two Point Maximum Frequency
Short descriptionDefines the maximum frequency for scaling the frequency input
ModeRFC‑A
Minimum0.00Maximum100.00
Default100.00Units%
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

See Two Point Minimum Frequency (03.047).


Parameter03.050  Drive Reference at Maximum Frequency
Short descriptionDefines the drive reference for scaling the frequency input at maximum frequency
ModeRFC‑A
Minimum0.00Maximum100.00
Default100.00Units%
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places2
CodingRW

See Two Point Minimum Frequency (03.047).


Parameter03.072  Motor speed percent
Short descriptionDisplays the final demand reference as a percentage of the reference clamp
ModeRFC‑A
Minimum-150.0Maximum150.0
Default Units%
Type16 Bit VolatileUpdate RateBackground write
Display FormatStandardDecimal Places1
CodingRO, FI, ND, NC, PT

Motor speed percent (03.072) displays the Final Demand Reference (03.001) as a percentage of the reference clamp.

If  Final Demand Reference (03.001) >= 0.00Hz then

If Maximum Reference Clamp (01.006) = 0.00Hz then

Motor speed percent (03.072) = 0.0%

else

Motor speed percent (03.072) = Final Demand Reference (03.001) x 100 / Maximum Reference Clamp (01.006)

else

If Negative Reference Clamp Enable (01.008) = 1 then

If Maximum Reference Clamp (01.006) = 0.00Hz  then

Motor speed percent (03.072) = 0.0%

else

Motor speed percent (03.072) =  -Final Demand Reference (03.001) x 100 / Minimum Reference Clamp (01.007)

else

If Maximum Reference Clamp (01.006) = 0.00Hz then

Motor speed percent (03.072)= 0.0%

else

Motor speed percent (03.072) =  -Final Demand Reference (03.001) x 100 / (-Maximum Reference Clamp (01.006))


Parameter03.079  Sensorless Mode Filter
Short descriptionDefines the time constant for the filter applied to the output of the frequency estimator system
ModeRFC‑A
Minimum0Maximum5
Default0Unitsms
Type8 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places0
CodingRW, TE

ValueText
04
15
26
38
412
520

A filter with a 4ms time constant is always applied to the output of the frequency estimator system used for sensorless operation in closed loop mode. This time constant may be extended by increasing Sensorless Mode Filter (03.079) above 0. The output of the frequency estimator can include some ripple, which increases as the drive passes into field weakening and the filter can be used to remove this ripple. This is particularly useful when using standard ramp or spinning start with a low friction high inertia load, and can prevent over voltage trips when the drive has no braking resistor.


Parameter03.080  Sensorless Position
Short descriptionDisplays the motor position representing a movement equivalent to one pole of the motor
ModeRFC‑A
Minimum0Maximum65535
Default Units 
Type16 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places0
CodingRO, ND, NC, PT, BU

Sensorless Position (03.080) gives the motor position representing a movement equivalent to one pole of the motor.

For example in a rotary application with a 4 pole motor, the movement associated with one pole is a mechanical movement of 180°. Sensorless Position (03.080) is aligned as for a position feedback device with 0° phasing angle.


Parameter03.127  Frequency feedback
Short descriptionFrequency feedback from encoder
ModeRFC‑A
Minimum−VM_SPEED_FREQ_REFMaximumVM_SPEED_FREQ_REF
Default UnitsHz
Type32 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places2
CodingRO, VM, ND, NC, PT

Frequency feedback (03.127) shows the frequency derived from the encoder feedback if Digital input 6/7 mode (08.036) = 2.  The value shown is measured over a 16ms sliding window period and will depend on Rotary Lines Per Revolution (03.134).


Parameter03.128  Revolution Counter
Short descriptionDisplays the revolution counter when in encoder mode
ModeRFC‑A
Minimum0Maximum65535
Default UnitsRevs
Type16 Bit VolatileUpdate Rate16ms
Display FormatStandardDecimal Places0
CodingRO, FI, ND, NC, PT, BU

Encoder revolution counter from 0 to 65535. If Digital input 6/7 mode (08.036) is 2 in Encoder mode, read 0 otherwise.

Counter is reset to 0 if Position Counter Reset (03.032) is 1.


Parameter03.134  Rotary Lines Per Revolution
Short descriptionDefines the number of rotary lines per revolution for the encoder connected
ModeRFC‑A
Minimum0Maximum3
Default1Units 
Type8 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places0
CodingRW, TE

ValueText
0512
11024
22048
34096

Rotary Lines Per Revolution (03.134) should be set to the number of lines per revolution for the encoder connected to the Di6 and Di7 inputs.


Parameter03.142  Encoder feedback filter
Short descriptionDefines the time period for a sliding window filter that may be applied to the feedback taken from the drive encoder feedback interface
ModeRFC‑A
Minimum1Maximum31
Default3Unitsms
Type8 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places0
CodingRW

Encoder feedback filter (03.142) defines the time period for a sliding window filter that may be applied to the feedback taken from the drive encoder feedback interface. This is a multiple of 16ms window. The encoder is sampled every 16ms and therefore if Encoder feedback filter (03.142) = 1 the filter is disabled.


Parameter03.143  Maximum Frequency Feedback
Short descriptionDefines the maximum frequency expected at the frequency encoder feedback
ModeRFC‑A
Minimum−VM_SPEED_FREQ_REFMaximumVM_SPEED_FREQ_REF
DefaultSee exceptions belowUnitsHz
Type32 Bit User SaveUpdate RateBackground
Display FormatStandardDecimal Places2
CodingRW, VM

RegionDefault Value
50Hz50.00
60Hz60.00

Defines the maximum frequency feedback expected in Frequency feedback (03.127)