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66 Unidrive SP Advanced User Guide
www.controltechniques.com Issue Number: 7
6, SC: SinCos: Encoder with no serial communications
This type of encoder can be used for motor control in closed-loop vector mode or servo mode. In servo mode a phasing test must be performed
after every drive power-up or encoder trip.
7, SC.Hiper: Absolute SinCos encoder using Stegmann 485 comms protocol (HiperFace).
This type of encoder gives absolute position and can be used for motor control in closed-loop vector or servo modes. The drive can check the
position from the sine and cosine waveforms against the internal encoder position using serial communications and if an error occurs the drive
initiates a trip. An applications or fieldbus option module can communicate with the encoder via parameters that are not visible from the keypad or
drive 485 comms.
8, EnDAt: Absolute EnDat only encoder
This type of encoder gives absolute position and can be used for motor control in closed-loop vector or servo modes. Additional communications
with the encoder from an applications or fieldbus module is not possible
9, SC.Endat: Absolute SinCos encoder using EnDat comms protocol
This type of encoder gives absolute position and can be used for motor control in closed-loop vector or servo modes. The drive can check the
position from the sine and cosine waveforms against the internal encoder position using serial communications and if an error occurs the drive
initiates a trip. An applications or fieldbus option module can communicate with the encoder via parameters that are not visible from the keypad or
drive 485 comms
10, SSI: Absolute SSI only encoder
This type of encoder gives absolute position and can be used for motor control in closed-loop vector or servo modes. Additional communications
with the encoder from an applications or fieldbus module is not possible. SSI encoders use either gray code or binary format which can be
selected with Pr 3.41.
11, SC.SSI: SinCos encoder using SSI comms protocol
This type of encoder gives absolute position and can be used for motor control in closed-loop vector or servo modes. The drive can check the
position from the sine and cosine waveforms against the internal encoder position using serial communications and if an error occurs the drive
initiates a trip.
All SINCOS encoders and encoders using communications must be initialised before their position data can be used. The encoder is automatically
initialised at power-up, after trips Enc1 to Enc8 or Enc11 to Enc17 are reset, and when the initialisation (Pr 3.47) is set to 1. If the encoder is not
initialised or the initialisation is invalid the drive initiates trip Enc7.
Ab, Fd, Fr, Ab Servo, Fd Servo, Fr Servo - Drive encoder termination select
The terminations may be enabled/disabled by this parameter as follows:
SC- Not used
Pr 3.39 has no effect.
SC.Hiper, SC.EnDat, SC.SSI - Rotary encoder select
If Pr 3.39 is set to 1 or 2 the encoder is a rotary encoder and the following apply:
1. Pr 3.33 defines the number of turns bits in the comms message from the encoder and a mask is applied to Pr 3.28 to remove turns bits in excess
of those provided in the encoder comms position.
2. The number of encoder lines per revolution defined by Pr 3.34 is forced to a power of two between 2 and 32768.
3. Pr 3.35 defines the number of comms bits used to define a single turn.
If Pr 3.39 is set to 0 the encoder is a linear encoder and the following apply:
1. Pr 3.33 defines the ratio between the length of a sine wave period and the length of the least significant comms bit.
2. No mask is applied to the turns displayed in Pr 3.28.
3. Pr 3.35 defines the number of comms bits used to give the whole position value.
3.39
Drive encoder termination select / Rotary encoder select / Comms only encoder mode
Drive modes Open-loop, Closed-loop vector, Servo
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
11
Range Open-loop, Closed-loop vector, Servo 0 to 2
Default Open-loop, Closed-loop vector, Servo 1
Update rate Background read
Encoder input Pr 3.39=0 Pr 3.39=1 Pr 3.39=2
A-A\ Disabled Enabled Enabled
B-B\ Disabled Enabled Enabled
Z-Z\ Disabled Disabled Enabled
U-U\, V-V\, W-W\ Enabled Enabled Enabled
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