2
0
2
0
-0
3
24
Communication with WCS Read Heads
Diagnostic function F0=1
The read head can be requested to perform a diagnosis of the photoelectrics via the request
byte to the read head. For this purpose, the read head must be located outside of the code rail.
On the WCS2B and WCS3B read heads, the degree of dirt accumulation on the photoelectrics
is monitored automatically during operation and the diagnostic bit (DB) set if dirt accumulation
is too high. Thus the request for diagnosis to the read head via F0 in the request byte is no lon-
ger necessary. However, for reasons of downward compatibility, this function is also supported
by the new read heads.
Diagnostic bit (DB)
Diagnostic bit DB displays the result of the integrated diagnostics of the read head.
Contamination detection
Read heads WCS2B and WCS3B continually monitor the condition of the lenses. If a drop in
light output is detected on the infrared transmitter, e.g., as a result of contamination of the clear
protective lenses, the read head automatically increases the light intensity. If the level of con-
tamination is too high, a warning message is sent to the higher-level control panel (diagnostic
bit DB=1). The automatic light adjustment in the read head allows you sufficient time to clean
the read head as part of the next servicing procedure. The WCS3B read head emits a visual
signal for the "contamination detected" state: the yellow and red LEDs on the front of the read
head flash alternately. To clean the lenses, the read head must be removed from the code rail
(removed from the mounting base). After cleaning the transparent protective lenses, the con-
tamination message is automatically deleted from the read head. If the message is not reset
despite careful cleaning or replacement of the plastic protective lenses, there may be an error.
In this case, the read head must be sent for inspection.
Function number for read head F0 = 1 (send diagnosis result)
ERR
DB
OUT
Description
State of the
read head
lens
0
1
0
Diagnosis invalid, read head not outside of the code rail -
0
1
1
Diagnosis result in P16 ... P18
-
P16 ... P18 = 0
Good
P16 ... P18 > 0
Poor
1
x
x
Error message from read head, error message in
P00 ... P04, binary coded
-
