12.2.3.3 SSI encoder
SSI absolute value encoders (Synchr
onous Serial Interface) generate the angle informaon via
opcal scanning of a code disc (e.g. Gray code). Every (absolute) angle posion of the encoder
corresponds to a uniquely idenable code paern.
All encoders that use the Stegemann SSI protocol are supported:
•
Support
ed bit rates for SSI communicaon: 150 ... 1000 kbits
•
Support
ed data word widths: 1 ... 31 bits (eecve)
•
Support
ed output code of the SSI encoder: Gray or binary
•
Cycle me: 62.5 µs, 125 µs and 250 µs .
•
Enc
oder supply: U < 12 V, I ≤ 0.25 A
How to parameterise the SSI encoder:
1.Set the supply voltage of the SSI encoder used in 0x2C52:002.
2.Set selecon "5: SSI encoder" as the encoder type in 0x2C50.
3.Set the transmission rate for SSI communicaon in 0x2C5A:001.
With the SSI protocol, the permissible transmission rate decreases as the cable lengths
increase. A safe transmission rate must be set according to the length of the encoder cable
used and the electromagnec interference level.
4.Set the telegram length in 0x2C5A:002.
The telegram length reects the number of data bits used for transmission of a complete SSI
data packet.
5.Break the received SSI data word down into partwords and, if necessary, acvate data con-
version of Gray into binary code.
Parameter
Address Name / seng range / [default seng] Info
0x2C5A:001 Protokoll-Parameter Lastgeber/Leitgeber (SSI): Über-
tr
agungsrate
150 ... [300] ... 1000 kbps
•
Seng can only be changed if the inverter is inhibi-
ted.
To enable a stable transmission rate, the length of the encoder cable
used and any electromagnec interference levels must be taken into
account when seng the value.
0x2C5A:002 Protokoll-Parameter Lastgeber/Leitgeber (SSI): Tele-
grammlänge
1 ... [25] ... 31
•
Seng can only be changed if the inverter is inhibi-
ted.
The set value species the number of data bits which are transmied as
a complete SSI data packet.
0x2C5A:003 Protokoll-Parameter Lastgeber/Leitgeber (SSI): Bits/
Umdr
ehung
1 ... [13] ... 31
•
Seng can only be changed if the inverter is inhibi-
ted.
Resoluon of the encoder.
For example, the resoluon for the preset value is "13":
2
13
= 8196 (bits/revoluon).
0x2C5A:004 Protokoll-Parameter Lastgeber/Leitgeber (SSI): Start-
bit Posionsdaten
0 ... [0] ... 30
•
Seng can only be changed if the inverter is inhibi-
t
ed.
Indicates the posion in the telegram where the posion data word
begins.
0x2C5A:005 Protokoll-Parameter Lastgeber/Leitgeber (SSI): Start-
bit Datenpaket 1
0 ... [0] ... 30
•
Seng can only be changed if the inverter is inhibi-
ted.
Indicates the posion in the telegram where data packet 1 begins.
0x2C5A:006 Protokoll-Parameter Lastgeber/Leitgeber (SSI): Start-
bit Da
tenpaket 2
0 ... [0] ... 30
•
Seng can only be changed if the inverter is inhibi-
ted.
Indicates the posion in the telegram where data packet 2 begins.
Conguring the feedback system
Sec
ond feedback system for the techology applicaon
Encoder sengs
196