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Interface description
NDRA91-92
Manual
Page 46
NADO
5.6
SSI Interface of
NDRA91
S
Specification
The
NDRA91
S is equipped with an SSI-data interface (SSI = synchronous serial
interface). By the SSI master the current measurement data is collected, it
sends to the clock for the shift register in the slave. The SSI slave sends its data
from the shift register bit by bit to the master. Depending on the length and
quality of the data cable transfer rates of 50 kHz to 1 MHz at 25 microseconds
interval time between two bit streams are possible.
The data length is 24 bits plus one validity bit. The format can be binary or
gray-encoded. For parameter settings via the serial interface, the SCx
command is available.
SCx
x=0...binary, 25 bits (24 bits plus 1 validity bit)
x=1...gray, 25 bits (24 bits plus 1 validity bit)
Bit stream:
24
23
..................................
2
1
0
MSB
Bit 1 – 24 distance depending on preset scale factor
LSB
*)
*) Bit 0: validity bit
Electrical Connection SSI
SSI (2)
Dummy (3)
Figure 23 SSI connection diagram
NDRA91
S M12 connector