T
Tv
Gn
G1
G0
Gn-1
Tm
SSI Data
Clock
Figure 8.
SSI-compatible
interface
timing
T
Duration
of clock signal: minimum 2
μ
Sec = 500
kHz; maximum 13
μ
Sec = 77 kHz
Tv
Delay
time
maximum 360 ns
Tm
Minimum
time
between last rising edge and
reloading of SSI, approximately 24
μ
Sec
Gn
MSB (here Gray Code)
24-bit Transmission
G1 = second LSB; G0 = LSB
24+E Transmission
G1 = LSB; G0 = error bit
25-bit Transmission
G1 = second LSB, G0 = LSB
SSI Cable
The maximum baud rate for reliable data transmission depends on the cable length. The shielded
connection
cable is connected to the
sensor connector and the ground terminal of the control cabinet.
Cable Lengths
Cable Length
< 25 m
< 50 m
< 100 m
< 200 m
< 400 m
Baud Rate
< 500 kHz
< 400 kHz
< 300 kHz
< 200 kHz
< 100 kHz
Troubleshooting
and Error Codes
When an error occurs, the error output Qs or Qp is set. The LCD displays an error message.
Multiple
errors may exist simultaneously. In this case, both Qs and Qp are set. The LCD displays the
respective
error messages. The error
status is requested via the RS422 GSI command. For example, a voltage that is too low causes a counter error. As a result, the GSI
command reports 00000110.
Error Message
Error Output
(Active
Low)
Bit Response
Sequence
Meaning
Qs
Qp
BLINDING
Active
01000000
Internal error or ambient light too strong.
LAS. ERR.
Active
Active
10000000
Measurement laser faulty: repair or replace sensor.
LOW VOLT
Active
Active
00000100
Voltage too low or error in measurement of supply voltage.
NO VALUE
00000000
First measurement
after
switching on: sensor not ready. The message
disappears
automatically
after
300 ms when the sensor is ready.
PLL UNLOCKED
Active
Active
00000010
Counter error: repair or replace sensor.
Active
00100000
Temperature is out of acceptable range (below –10 °C or above +70 °C ).
OVERTEMP
Active
(Laser OFF)
Active
(Laser
Off)
00101000
Operating
temperature is too high (above +85 °C inside the housing). The
measurement laser switches
off.
Turn the sensor
off.
The sensor may
operate again
after
a cool-down period.
DIST (mm) >
Maximum
Active
00010000
No target in range or misaligned sensor.
CAUTION: Do Not Disassemble for Repair
This device contains no user-serviceable components. Do not
attempt
to disassemble for repair. A
defective
unit
must be returned to the manufacturer.
L-GAGE
®
LT7 Long-Range Time-of-Flight Laser Sensor
16
www.bannerengineering.com - Tel: +1-763-544-3164
P/N 120244 Rev. C
