iC-LNG 16-BIT OPTO ENCODER
WITH SPI AND SERIAL / PARALLEL OUTPUTS
Rev A1, Page 23/25
LED CURRENT CONTROL
LCSET(5:0)
Add. 0x06, bit 5:0
LCSET(6) = 0
0.240 Vp
The optical receive power of the sine/cosine sensors
Code
0x00
0x01
...
LCSET(6) = 1
0.140 V
is kept constant by the integrated LED control unit, re-
gardless of the temperature and ageing effects of the
LED. The type of control can be selected using param-
eter LCSET(6), the possible options being sum control
or square control. So that the internal interpolator is
always optimally controlled in all operating conditions,
square control should be used. Sum control should be
used for signal conditioning.
0.243 Vp
0.24 Vp
1−i·0.0125
1.1 Vp
0.142 V
0.14 V
1−i·0.0125
0.640 V
0x3F
Table 29: Control Setpoint
Error Monitoring
LCSET(6) Add. 0x06, bit 6
iC-LNG’s LED current control range is monitored.
Should the LED current control exit its control range,
internal error ERRS is set to 1. This error signal is or-
gated with iC-LNG’s ERRP alarm (parity check) and
output at error output ERR (cf. section on the alarm
output).
0
1
Square control (sum of the amplitude squares)
Sum control (DC control prop. to VR())
Table 28: Control mode
The setpoint for the control can be configured using
parameter LCSET(5:0).
ALARM OUTPUT
iC-LNG has an alarm or error output to indicate exist-
ing errors. If an error occurs, pin ERR is set to 1.
ER RO R ME SSA GE
VD D
ER R
G ND
iC-LNG’s LED current control range is monitored.
Should the LED current control exit its control range,
internal error ERRS is set to 1.
ER RS
ER RP
³1
If the parity check signals an error in the RAM area,
internal error ERRP is set to 1.
Figure 18: Alarm output
ICHAUS [ IC-HAUS GMBH ]
