Page
4 D-LX
100
4. Self-Check
The D-LX 100 All-In-One Flame Scanner is fail-safe and self-checking, in accordance with European
EN standards for flame scanning equipment. After power-up, the flame scanner performs a self-
check, which is constantly performed during continuous operation.
If employed for continuous operation, any component failure that jeopardizes the safety-related
functions of a scanner must trigger an error shutdown. The D-LX 100 is therefore equipped with a
dual-channel microprocessor system. This system controls all functions and self-checks, and
monitors all safety-related timing sequences. Input and output status is independently checked and
compared by the microprocessors. Only if they agree is operation allowed to continue.
If the controller signals flame ON, the integrated flame scanner is automatically monitored. This
occurs every second for 0.2 s via the activation of a shutter. The shutter is a transistor separating the
photo element from the electronics. In the case of the D-LX 100 UL, a long-lasting mechanical shutter
is used to interrupt the path from the photo element to the electronics. The interruption of the
photocurrent simulates the outage of a flame and must result in a drop in the flame signal that was
present during the 0.8 s that the scanner was monitoring the flame. If a hardware problem causes too
little a decrease in the flame signal, an error shutdown will occur after eight such cycles, that is, after
eight seconds.
If the flame ON signal is stopped, the integrated flame scanner is also no longer checked.
5. Fault
If the internal self-check recognizes an error in the safety-related software and hardware components,
an error shutdown and internal lockout must be triggered. The relays for the flame, operational
readiness and fault signals are released, and the red LED on the front panel will begin blinking. The
contact from K1 signals the present fault.
The red LED blinks 5 times by itself. After that, the yellow LED will also begin blinking with the red.
The number of times that the yellow LED blinks corresponds to the type of error, which allows the
operator to precisely analyze the source of the fault. The following error sources can be signaled:
5.1. Error Codes of the 1
st
CPU:
Error
Code
Yellow
LED
Blinks
Source of Error
Possible Cause of the Error
1. 1
x
Synchronization defective
/ faulty microprocessor circuit
2. 2
x
2
nd
CPU
2
nd
CPU is indicating an error (no display of its own)
3.
3 x
FOS cycle
defective cycle generation / faulty acknowledgment
4.
4 x
Flame signal relay
defective drive / faulty acknowledgment
5.
5 x
Flame signal contact
defective / faulty acknowledgment of the contact
position
6.
6 x
Status signal relay
defective drive / faulty acknowledgment
7.
7 x
Flame comparison
faulty transmission of flame data
8.
8 x
Flame recognition
threshold
push button switch on front panel pressed by
unauthorized personnel
9.
9 x
Safety time
unauthorized change in the soldering field
10.
10 x
PROM test
defective / faulty microprocessor circuit
11.
11 x
RAM test
defective / faulty microprocessor circuit
12.
12 x
Flag test
defective / faulty microprocessor circuit
13.
13 x
CPU test
defective / faulty microprocessor circuit
