General Description
The SICK Stegmann CKS series of encoders are incremental encoders with commutation tracks. They have a threaded shaft which screws into the motor side, and that makes physical realignment nearly impossible. The TI-5720 test cable has special connections going directly to the encoder which allow for electronic realignment.
TI-5720: https://bobcat.mitchell-electronics.com/parts/478
Operation
- As always, make sure you have recorded the original alignment of your motor before proceeding with feedback removal. The encoder can only be reset to the 0 electrical degree position. You must find that 0 degree lockup combination on your motor, be it a line-to-line or line-to-neutral lockup combination.
- Install the encoder and connect the TI-5720 cable directly the back [Fig1]. Rotating the encoder body CW will tighten it to the motor; CCW encoder rotation loosens it from the motor. Make sure the 2 encoder mount screws are installed and fully tightened which release the encoder shaft lock.
- Connect J1 and J2 of the TI-5720 to the TI-5000JX. Power on the tester and select "Generic Incremental Encoder‟ from the Feedback Selection menu.
- Make sure you have the correct number of counts/rev entered in the Feedback Selection menu and that you have the correct number of motor poles entered in Data Display. If either setting is incorrect, your electrical angles will also be in correct. Perform a Count Test to verify proper counts. In Data Display, make sure the encoder has been indexed and that the angles change respectively with encoder rotation.
- Lockup the motor UVW leads with the 0 degree lockup polarity found in step 1.
- Use a clip lead to jumper the “FREE” orange wire of the TI-5720 to the screw ofJ1 pin 1 (+5VDC) for 1 second [Fig.2]. The encoder has now been reset to 0 electrical degrees but will not show on the screen until you refresh Data Display.
- Click the Data Display button and re-index the encoder. Use the same lockup as before and now you should see that your encoder angle is set to 0 electrical degrees.
Notes
- Some of the CKS encoders can be programmed to output various count resolutions and motor poles (commutation track sequences). These models have “PFBPROG PROG” written on the encoder label. CKS encoders without this label have permanent count and pole resolutions. There are two other free wires on the TI-5720 test cable (Red/Black andRed/White) which are used for programming these encoders. However, this programming feature is currently unavailable on the TI-5000JX. The wires are left on for future development.
- The Stegmann incremental encoders (CKS, CNS, CDD, etc) output commutation tracks in a format this is not typically used by the common motor manufactures (see Fig. 3).The commutation wires are typically rearranged when routed over to the motor feedback connector. This means that the commutation signal states will likely appear different when connecting to the encoder directly (TI-5720) compared to connecting through the motor feedback plug. Always use the motor feedback connection to document the alignment of the commutation signal states instead of the TI-5720.
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