AKD FAQ (EN)

This encoder has never been operated with any of our servo drives. The HSAVE ERASE command requires the user memory to be formatted.

Does the encoder use more than 25 bits? If yes, the explanation is that former firmware versions do not support these encoders. Update as below:

S400: use version 7.xx
S600: use version 6.xx

This occurs because the setup software is resetting "Motor with Brake" to "Motor without Brake".

Fix: Use the terminal screen and enter the ASCII commands MBRAKE1 HSAVE.

Explanation: The motor options are saved in the ENDAT encoder. If this information is wrong, the brake option in the drive is always reset.

In all likelihood the application was installed in 2004. The old motor had a built-in EnDat encoder with small memory range. Heidenhain changed the memory range of EnDat encoders in 2005 (see FAQ Feedback).

EnDat encoders with expanded memory range can be evaluated with all S300/S700 drives and with S400/S600 drives from firmware version 4.94.

For applications with firmware version lower than 4.94, the firmware version 3.67 must be loaded, which has been produced for this purpose ([[File Selector]]).

S300/S700: from 3.00
S400/S600: from 6.68 (not 7.xx)

S300: 2.1
S400: 2.1
S600: 2.1
S700: 2.1 and 2.2

All amplifiers can work with 2.2 protocol in compatibility mode 2.1.

The following BiSS-C encoders are known to work with an AKD drive. This list does not include BiSS Mode B encoders, which function differently.

Configuration requires that FB1.SELECT be manually set to 34, and that FB1.BISSBITS and FB1.ENCRES be set according to the values/equations in the table above.

Full Setup Procedure for a BiSS-C Encoder:

1. Configure the motor properly. For linear encoders, make certain that the pole pitch is correct for the given motor.
2. Refer to the encoder datasheet to determine the number of BiSS bits expected from the device. Use the terminal to set FB1.BISSBITS to this number.
3. Under the "Settings->Feedback 1" tab, select "34 - BiSS Mode C Renishaw", then "Disable & Clear Faults". The encoder should now be returning data.
   1. If faults are being generated, first try Switching to "1 - None", the go back to "34 - BiSS Mode C Renishaw".
   2. If faults are still being generated, then the likely causes are:
      1. The FB1.BISSBITS value does not match the number of bits from the encoder. Recheck the datasheet & encoder
      2. There is a grounding issue and the communication lines are too noisy to return position data. Make sure the cable shield is correctly wired.
      3. The encoder may be using active high error bits instead of active low error bits. Verify this is not the case on the datasheet. For example, the LMA10 encoder series has active high error bits unless option 03 is used. As a result, non "option 03" LMA10 encoders will not work with the drive.
4. Once the drive is communicating with the encoder and showing position feedback, the FB1.ENCRES (on some drives, FB1.ENCLINES) needs to be set.
   1. Use the table above to set FB1.ENCRES for known encoders.
   2. The general equation for linear encoders is: (pole pitch / encoder resolution) * 2^(32-BISSBITS). On 1.12.05.00 firmware, this will be (pole pitch / encoder resolution) * 2^(BISSBITS-32).
   3. Single-turn rotary encoders are always 2^32-1 = 4294967295.
   4. Multi-turn rotary encoders are always 2^(32 - (Number of Multi-turn bits)).
5. If the encoder is still giving completely wrong position values, try working in reverse to determine the approximate value for ENCRES, then use that to verify your previous equation had the right input parameters. This is more useful when the encoder datasheet isn't entirely clear on what distance is measured by one LSB of the encoder.
   1. Set ENCRES to 65536 (2^16).
   2. Record the current position value in counts
   3. Move the encoder by one complete pole pitch or rotate the shaft one complete revolution
   4. Record the new position value in counts.
   5. Take the difference between the two, then divide by 65536. This is approximately what ENCRES should be.
   6. The encoder resolution is then approximately (pole pitch * 2^(48 - BISSBITS)) / (position 2 - position 1) for linear encoders.
6. If, after trying all troubleshooting steps, the encoder is still returning incorrect values or does not work, please report the issue. Make sure to report which steps you were able to complete, what faults were generated, the exact model of the encoder, and a complete parameter dump from the drive.

The 5V type is always used.

AA always describes a single turn type and AB a multi turn type.

AKM motors use resolvers manufactured by Harowe. Harowe defines vibration resistance with 10G (98m/s²) and shock resistance with 50G(490m/s²).

The Heidenhain encoder series (ECI/EQI 11xx, 13xx and ECN/EQN 11xx, 13xx) are defined according to IEC 60068-2-27 with a max. shock resistance of 102G (1000m/s²) for 6s.

14 bits. The theoretic resolution in the position loop is 20 bits.

11 bits. These are 2 bits for signal quadrupling and 8 bits signal resolution plus 1 bit sign. The signals have an internal resolution of 12 bits but operated with 8 bits.

The SinCos amplitude monitoring enables the F04 error with:

• Level min/max (see page Supervision of Sine Cosine Encoders)
• no communication to the encoder

Solution: connect the encoder, check the cable

• Wrong data in the encoder

This error occurs with new encoders, that have never been initialized
Solution: Initialize the data with the command HSAVE (terminal screen)

• Linear measuring system is used

Feedback cable shielding
Solution: see Sporadic Error Message F04 with Linear Measuring Systems

See pages Supervision of Sine Cosine Encoders, Setup of an Endat or Hiperface or BISS encoder, and AKD LED Display or Servostar LED Display.

The BiSS encoder nominally has an accuracy of +/- 35 angle seconds. In the laboratory +/- 20 angle seconds have been measured.
A comparable Heidenhain encoder has nominal +/- 60 angle seconds accuracy.

• A faulty connection, such as a damaged cable, is the reason for this error message. Check to ensure the connection is tight and inspect the cable.
• An unsupported encoder produces the message "unknown type".

• incorrect sine signal at one of the threee motor phases
• sine signal weak or interrupted (within 360°)

Remark: no error message with S600!

By default, S300 and S700 check  the X1 sense lines (feedback voltage supply). In Master-Slave or Electr.Gearing operation no supply voltage is required and the sense lines are not connected.

Solution: Bit 20 of parameter DRVCNFG2 of the servo amplifier disables the supervision of the sense lines (DRVCNFG2=DRVCNFG2+1048576).

The table below gives an overview of the different encoder types with the serial number of the corresponding motors and the week of delivery for built in encoders with extended memory range.

The first encoder serial number has been defined beside the index: 15 187 112.

Both conditions (encoder index and serial number) must be fulfilled for real memory range change. Heidenhain says, that there could be a small range of encoders that don't fulfill both conditions but nevertheless have the extended memory range.

Yes. A Wake and Shake function determines the absolute position of the permanent magnets in relationship to the stator windings. See page Wake and Shake.

No. With the S200 drive, SFD3 is not compatable. SFD must be used with S200.

The external zero pulse can be detected with the macro command "M NIZFLAG".
(send "M NIZFLAG 0" first to delete the existing value!)

See page Data storage in Endat or Hiperface or BISS encoders

See page SSI Encoder Evaluation.

See page Positioning with external SSI encoder.

See page Setup AquadB 5V encoder

To change direction you must exchange sine and cosine.

For more information refer to Motion direction - Parameters.

Direction of Hall signals are inverted with the command HALLDIR 1 (S300). Please observe, that this inverts the primary feedback, too. Change DIR from 21 / 20 to DIR 84 / 85 in this case.

For more information refer to Motion direction - Parameters.

Switch FBTYPE to 4 und save with HSAVE. Then switch FBTYPE back to the correct setting.