USER'S GUIDE  ____________________________________________________________________ 
160  __________________________________________________________________ M211187EN-C 
Error Messages 
Errors 
Table 29  Error Messages 
RESPONDING 
Measurement unit FSM102 or 
Background Luminance Sensor 
LM21 not responding to data 
poll from FSC202. 
Check the wire connections 
Open the sensor cover and verify that the 
green status LED is blinking and the red 
reset LED is not lit. If this is not the case 
there is a fault in the RS-485 line between 
If all the LEDs are off on the sensor board, 
there is power failure. Check the input power 
error, configuration not valid. 
Clear all configuration parameter settings 
with the SET DEFAULTS command. 
Reconfigure the needed parameter settings 
and give a reset. 
If the error still exists, there is a CPU board 
failure or a memory bus failure in FSM102. 
In FSM102 disconnect the control cables of 
the optics heads from the FSC102 and give 
a reset. 
If the memory error disappears, there is a 
cable failure, or the transmitter or receiver is 
jamming the memory bus. Locate the failed 
part by connecting one cable at a time to 
FSC102 and verifying after a reset with 
which part the problems occurs.