Ssi Communication Protocol; Ssi Communication Timing Chart - NSD ABSOCODER NCV-220HSSILC Specifications & Instruction Manual

9-2. SSI Communication Protocol

bit 1 2 3 4
data 0 D D D
23 22 21
(1) Set the following of the host PLC side.
- Absolute Sensor *1 (the data length): 25-bit.
- Steps/Revolutions *1: 8192.
*1 The items name is written when using SM338 manufactured by SIEMENS AG.

9-3. SSI Communication Timing Chart

CLK
DATA
(1) The newest DATA is latched and MSB is sent to the DATA line when the first CLK rises.
After that, the DATA is sent at each clock rising until LSB.
The DATA will be "L" after DATA is sent until LSB. (monoflop time)
(2) The same DATA will be sent from MSB again when the CLK is supplied newly within monoflop time.
The DATA becomes "H" when the CLK isn't supplied newly within the monoflop time.
After time passes more than monoflop time, the newest data will send from MSB again when CLK rises.
5 6 7 8 9 10
D D D D D D
20 19 18 17 16 15
bit1 bit2
MSB
11 12 13 14 15
D D D D D
14 13 12 11 10
bit24
bit3
37
16 17 18 19 20 21
D D D D D D
9 8 7 6 5
Monoflop time: 20μs
bit25
LSB
22 23 24 25
D D D D
4 3 2 1 0