SSI Encoder Evaluation

Valid for S300, S700 from FW 2.14

Parameter setup for SSI Encoder evaluation

A SSI encoder (absolute encoder) must be setup with these parameters:

• SSIRXD  – number of SSI bits to read
• SSIREVOL  – number of bits for multi-turn information
  These parameters are used to calculate the number of bits per encoder rotation = SSIRXD - SSIREVOL

• SSIGRAY = 0 binary coded
                 =1 gray coded
• ENCMODE=0 SSI interface used as input
• SSITOUT = 0 1MHz SSI-Clock
                 = 1 500KHz SSI-Clock
                 = 2 250KHz SSI-Clock  (only ext. position feedback)
                 = 3 125KHz SSI-Clock  (only ext. position feedback)
• SSIINV      = 0 SSI-Clock not inverted (see connection drawing)
                   = 1 SSI-Clock inverted 

All setting can done in the setup software or in a terminal program. Parameter overview see page Parameters for SSI Interface.

The SSI encoder can be used for

1. primary feedback   FBTYPE=9
   with this setting the SSI encoder is configured as commutation feedback.
   Update rate 62,5 µ
2. external position feedback EXTPOS=5
   with this setting the SSI encoder is configured as position feedback
   Update rate 125 µsec @ DPWM=3 (8 KHz position control)
                         250 µsec @ DPWM<>3 (default; 4 KHz position control)
   EGEARI, EGEARO sets the gearing ratio for the external gearing
3. master information for MasterSlave operation GEARMODE=5
   Update rate 250 µsec
   GEARI, GEARO sets the gearing ratio for the master-gearing

The SSI data are stored in the varable CNTSSI, format refers to the value of SSIRXD and SSIREVOL.

Connection