SICK DL1000, Operating Instructions Manual

Page: 19 / 122

3.7.2 SSI (synchronous serial interface)
The SSI interface makes possible serial data transmission of the distance value or of
the distance value combined with the status information. Clock and data are transfer‐
red over the interface. The data is transferred upon request from the control system.
For this purpose, the connected control unit applies a pulse sequence to the receiving
input of the measuring device. At each positive pulse edge, a data bit is pushed
onto the measuring device’s transmission line. This starts with the highest-value bit.
There is a pause of at least 30 µs between two pulse sequences. The cycle time and
transmission rate can be adjusted in wide limits on the control side. The bit pulse is
between 70 kHz and 500 kHz and is dependent on the length of cable,
see "Wiring
instructions", page 50 .
1 2 3 4
T
tv tm
Tp
Gn G1 Gn-
1
G0
m
Clock
Monoflop P/S
Data serial
Data parallel
Figure 6: Pulse diagram
Gn Most significant bit in the Gray code
G0 Least significant bit in the Gray code
m Stored parallel information
tm Monoflop time 20 µs
tv Delay time: First clock max. 540 ns, all further clocks max. 360 ns
T Period duration of a clock signal
Tp Clock pause
Depending on the set SSI coding ( "Defining SSI coding", page 85 ), the SSI telegram is structured according to the
following tables. For more information on the SSI status bits, see table 33, page 100 .
Table 6: Gray 24 or binary 24: 24 gray or binary measured value bit
MSB LSB
Bit23 Bit22 Bit21 Bit20 Bit19 Bit18 ... Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
M24 * M23 M22 M21 M20 M19 ... M7 M6 M5 M4 M3 M2 M1
* M = Measured value bit
Table 7: Gray 24+1 or binary 24+1: 24 gray or binary measured value bit +1 error bit (binary)
MSB LSB
Bit24 Bit23 Bit22 Bit21 Bit20 Bit19 ... Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
M24
1
M23 M22 M21 M20 M19 ... M6 M5 M4 M3 M2 M1 S1
2
DE, AE
3
1 M = Measured value bit
2 S = Status bit
3 DE = Device error, AE = Application error
PRODUCT DESCRIPTION
3
8024560/1A19/2021-06-30 | SICK O P E R A T I N G I N S T R U C T I O N S | DT1000 PROFIBUS DP and DL1000 PROFIBUS DP 19
Subject to change without notice