SSI Mode Principle Description

General

The SSI (Synchronous Serial Interface) mode allows the connection of an absolute encoder.

The position of the absolute encoder is read by an SSI link.

Principle Diagram

The following diagram provides an overview of the encoder in SSI mode:

G-SE-0074544.1.gif-high.gif

 

 

Principle Diagram

The figure below represents an SSI frame:

G-SE-0002948.1.gif-high.gif

 

 

Data Information

The data content can be configured to adjust the information from the absolute encoder:

Parameter

Range

Comment

Transmission speed

100 kHz, or

250 kHz, or

500 kHz

Number of bits per frame

8...64 bits

Length of frame = implicit number of header bits (0 to 4) + number of data bits (8 to 32) + number of status bits (0 to 4) + number of parity bit (0 or 1).

Number of data bits

8...32 bits

The least significant bits (8…32) indicate resolution per turn and the most significant bits (0…24) indicate the number of turns.

Number of data data/turn

8...16 bits

Number of status bits

0...4 bits

Parity

None

Odd

Even

Resolution reduction

0...17 bits

This parameter allows to filter data. The least significant bits are ignored.

Binary coding

Binary

Gray

Binary or gray code.