Feedback Settings


The AKD2G offers a variety of feedback solutions which allow you to optimize your system based on your specific machine needs. The table below lists the currently supported feedback types with associated connector/feedback ID. Your motor model number will indicate the type of feedback that you have.

Kollmorgen motors with digital feedback devices (such as SFD, EnDat, BiSS, HIPERFACE and, Tamagawa) are plug and play. With these motors, all feedback and motor settings are configured automatically. Third party motors, or Kollmorgen motors with non-digital feedback types, require parameters to be entered manually. See Non-Plug and Play Feedback Devices.

Feedback Devices

There are two views which allow you to configure your position feedback devices and provide information about them. The Feedback Devices view provides up-to-date data about the devices. Clicking on the feedback number field opens a Feedback View to configure it.

Element Description Parameter
X# Indicates the connector used for the feedback  
Feedback # block [number] Identifies the feedback and serves as a link to the configuration view  
Type Indicates the feedback type identified FB#.IDENTIFIED
Resolution Resolution of the identified feedback FB#.RES
Position Current position in raw feedback counts FB#.P
Graphical Indicator Visually indicates the position of the feedback within one revolution  
  FB Usage Indicates how the feedback is being used by an axis. Clicking an entry will open the view configuration.  

Feedback View

Each feedback device has its own view for detailled configuration. This view is used to set up your system to match the proper feedback device. By default, the drive assigns Feedback 1 to Axis 1, Feedback 2 to Axis 2, and uses the Auto Identify setting to detect feedback devices. This setting allows the drive to test the feedback device to see if it is a recognized plug and play device. If the drive recognizes the device, then all parameters for that device and motor are loaded into the drive. Both the feedback and the motor information are now present in the drive and the system is operable.

Scaling For Use Within WorkBench

Feedback linked to an axis Feedback not linked to an axis

The units and scaling of feedback linked to an axis are not configurable because the axis defines the units and gearing values which are set up in the Units view (see Selecting Units for Your Application).

The default settings provide scaling in degrees. One revolution of rotary feedback in the positive direction advances the position by 360 degrees.

Scaled Feedback that is not linked to an axis uses the settings found in the Monitoring section of this view.

This is typically used to send the feedback position to an external controller via a fieldbus.


This section of the Feedback view provides the current state of the feedback device.

Element Description Parameter

Provides live data showing the relative position within a revolution of the feedback device. The Mechanic Type setting determines whether the meter type.

Resolution Displays the resolution used for the device. Rotary devices are counts / mechanical revolution, linear devices are counts / pole. FB#.RES
Position Displays the raw position of the feedback device in counts. FB#.P


This section of the Feedback view provides for defining the feedback device.

Element Description Parameter
Feedback Selection Specify the type of feedback automatically or manually. See Feedback Types below for a description of each type. FB#.SELECT
Feedback Identified This parameter is set according to FB#.SELECT on drive power up if FB#.SELECT is not –1. Otherwise the parameter value is read from the drive memory. FB#.IDENTIFIED
Mechanic Type Select whether the feedback is a rotary (0) or linear (1) encoder. FB#.MECHTYPE
Encoder Resolution Configure the number of lines per revolution for rotary encoders or the line pitch (nm/line) for linear encoders. FB#.ENCLINES (for rotary) or FB#.LINEPITCH (for linear)
Multi-turn Sensor Bits Number of multi-turn bits used for BiSS encoders when used in rotary motors. FB#.MULTITURNBITS
Single-turn Sensor Bits Number of single turn bits used for BiSS rotary encoders. FB#.SINGLETURNBITS
Feedback Poles Sets the number of individual poles in a Resolver feedback device. This variable is used for the commutation function, as well as for velocity feedback scaling, and represents the number of individual poles (not pole pairs). FB#.POLES
Transformation Ratio Sets the Resolver nominal transformation ratio. It affects the resolver excitation output amplitude. FB#.RESKTR
Phase Lag Sets the electrical degrees of phase lag in the Resolver. FB#.RESREFPHASE

If the feedback is a non-plug and play device, then you can choose from the list of supported devices in the Feedback Selection list and enter the feedback settings manually. The following sections describe each supported device available in the Feedback Selection list and the input information required to configure each device.

FB#.INFO can be used to read additional information about the feedback when it is available.

Feedback Types

Value Type Description
-1 Auto Identify This is the default setting for Feedback 1 and 2 and is used to determine if a plug and play device is available. If a plug and play device is available, the FB#.IDENTIFIED keyword indicates the feedback device is detected. FB#.RES is updated with the resolution of the detected feedback.
1 No Encoder This setting can be used if no feedback device is connected to the associated feedback connector.
10 Incremental Encoder with Halls

Incremental encoders are available in a variety of line counts. If you select an incremental encoder option, the encoder resolution must be entered into the Encoder Resolution box or by setting FB#.ENCLINES. The units for this field are in lines per revolution. Wake and Shake will be enabled when using incremental encoders without Halls sensors.

11 Incremental Encoder without Halls
13 Step / Direction

This mode is intended to be used by controllers to provide a Electronic Gearing source signal. The A line pulses for each step and the B line indicates the direction. Encoder Resolution (FB#.ENCLINES) is used to configure how many pulses per revolution there are.

14 CW / CCW

As with Step/Direction, this mode is intended to be used as a Electronic Gearing source signal. The A line controls pulses in the clock wise direction and the B line control pulses in the counter-clockwise direction. Encoder Resolution (FB#.ENCLINES) is used to configure how many pulses per revolution there are.

20 Sine Encoder with Halls A sine-cosine uses a sine wave to indicate rotation. As with the incremental encoder, the line count is entered in the Encoder Resolution box or by setting FB#.ENCLINES. The actual resolution is much higher than the encoder line setting from measuring the analog signal. Wake and Shake will be enabled when using sine encoders without Halls sensors.
21 Sine Encoder without Halls
30 EnDat 2.1 - Analog

EnDat uses a sine encoder to indicate position with an analog signal.

31 EnDat 2.2 - Digital

EnDat supports both digital only and sin/cos analog signals and may only support digital only depending on encoder model.

34 BiSS Mode C - Digital

These feedback devices are all digital. See manufacturer specs for more information.

36 SSI

Select the type of SSI (Synchronous Serial Interface) device. The SSI Type field defines the manufacturer model and protocol used. The protocols differ in the data format of the serial position bits, and may contain special configuration and flag bits.

Value Protocol Models
0 Binary position bits only Netzer DS-25-SF-S0
1 Grey code position bits only Hengstler AD34/1217AF.0NSC0:5942

1 status bit

Grey code position bits

3 flag bits

1 zero bit

Gurley VP12S08A2CN

See also FB#.SSITYPE.

40 Resolver

The resolver feedback is an analog signal. When selecting the resolver option, the resolver specific parameters phase lag, transformation ratio, and feedback poles are set for AKM motors.

  • The resolver frequency is set to 6875Hz and cannot be adjusted.
41 SFD (Smart Feedback Device) Smart Feedback Device (SFD) is Kollmorgen's most popular plug and play device. SFD allows for quick and easy setup from the Auto mode, which automatically configures the drive with the motor and feedback parameters. SFD3 only requires 2 wires while SFD requires 4 wires.
45 SFD3 (Smart Feedback Device Gen3)  

These feedback devices are all digital. See manufacturer specifications for more information.

Control Loop Feedbacks

The default source for Axis 1 is Feedback 1, and for Axis 2 is Feedback 2. This means only SFD3 and HIPERFACE DSL are supported by default. To use other feedbacks, AXIS#.IL.FBSOURCE must be changed to 3 for Feedback 3 and Feedback 3 must be setup for the desired feedback or SFA.

Each axis has a set of control loop feedback sources:

AXIS#.OPMODE determines which control loops are active, and therefore which feedback sources are used.

The default control loop feedback sources corresponds to the axis. For Axis 1, the feedback sources default to Feedback 1. For Axis 2, the feedback sources default to Feedback 2.

Two-wire feedbacks (SFD3 and HIPERFACE DSL) and feedbacks connected via SFA can be used with the default feedback sources. When other feedback connections, such as Feedback 3, are used as control loop sources, the FBSOURCE parameters must be set accordingly.

Scaled Feedback

For feedback not associated with an axis, a set of scaled feedback parameters are provided to optionally represent the feedback position in scaled units.

The Scaled Position is calculated as follows:

FB#.SCALED.DIR Direction Sign
0 1
1 -1


There are separate feedback sources for the current, velocity, and position loops. By default they’re all set to the current loop feedback source (AXIS#.IL.FBSOURCE). If a separate feedback is desired for the different loops, those sources can be set independently using AXIS#.VL.FBSOURCE and AXIS#.PL.FBSOURCE .

Electronic Gearing

For Electronic Gearing, AXIS#.GEAR.FBSOURCE is also available. See the Electronic Gearing feature for more information.

Feedback to Connector Mapping

Feedback Connector Mapping

AKD2G Feedback Connector AKD2G Feedbacks
X1 FB1
X2 FB2
X23 FB3
X21 FB4
X22 FB5

Feedback Types Supported on Each Connector

Feedback Types Supported

Feedback Type


FB1 (X1)

FB2 (X2)

FB3 (X23)

FB4 (X21)

FB5 (X22)

Plug & Play

SFA-R00 (X41)

SFA-E00 (X41)

Incremental Encoder

With Halls and Index







No Halls with Index






No Halls and No Index


















Sine Encoder

With Digital Halls







With Digital Halls and Analog Index






No Halls and No Index






EnDat Analog

Single and Multi-Turn






EnDat Digital

All digital










BiSS-B Analog

All Analog








All Analog







BiSS-C Digital

All Digital






Std and Multi pole





















All Digital




SSI Synchronous Serial Interface          

Smart Feedback Adapter

Kollmorgen provides an optional Smart Feedback Adapter (SFA) to allow feedback devices that normally connect to X23 (FB3) to connect through X1 (FB1) and X2 (FB2) instead. For example, on a dual axis drive requiring two resolver feedbacks, X23 could be used for one feedback and an SFA on X2 could be used for the other feedback. See Feedback Connector X41 for details on connecting SFA hardware to AKD2G.

For connections that support SFA (X1 and X2), SFA feedback types can be selected using FB#.SELECT in the same manner as other feedbacks. If they are plug-and-play, FB#.SELECT can be set to -1 to auto-identify them. SFA feedback types appear as options for FB#.SELECT when the corresponding feedback connector supports SFA. For example, FB1.SELECT and FB2.SELECT show the SFA feedback types as options. See FB#.SELECT for a list of supported SFA feedback.

When the feedback is selected (see FB#.SELECT), the SFA is programmed with an FPGA image automatically if needed.

SFA cable flying leads connected to X1 (FB1, EEO3) or X2 (FB2, EEO4):

Commands Used for Each Feedback

FB#.SELECT Incremental Encoder with Halls Incremental Encoder without Halls Sine Encoder with Halls Sine Encoder without Halls EnDat Analog EnDat Digital BiSS-B Analog HIPERFACE SSI BiSS-C Digital Resolver SFD SFD3 HIPERFACE DSL
10 11 20 21 30 31 32 33 36 34 40 41 45 46
FB#.SINGLETURNBITS               ✔ (R) ✔ (R)        
FB#.MULTITURNBITS               ✔ (R) ✔ (R)        
FB#.BITS                 ✔ (L) ✔ (L)        
FB#.ENCLINES ✔ (R) ✔ (R) ✔ (R) ✔ (R)                    
FB#.LINEPITCH ✔ (L) ✔ (L) ✔ (L) ✔ (L)         ✔ (L) ✔ (L)        
FB#.RES ✔   ✔  
FB#.USERBYTE, FB#.USERWORD, FB#.USERDWORD         Future Future          

(R) = Rotary

(L) = Linear