54733-10BA2L
1 – 100 02.2017
7 Functional Safety Volume 1
7.6 Device Behavior during Operation
7.6.1 Device Behavior after Power On
After power on, a diagnosis phase of 15 seconds starts in which the
measuring device is checked for errors. The current output changes
to 24mA for 2 seconds and then to 0mA. During this time, no com-
munication with the device is possible.
If an error is detected during the diagnosis phase, the device
changes to fault current. In the other case, a current in the range
between 3.8 ... 20.5 mA is output.
7.6.2 Behavior of the Current Output in Case of
Error
If the measuring device detects a fault, the current output is
brought to a safe condition.
Error >21mA or <3.6mA:
There is a hardware or software error.
Please refer to the operating manual for a detailed description of the
error behavior.
7.6.3 Device Behavior in Case of Interference Radia-
tion
The LB 480 is able to detect interference radiation caused, for
example, by weld seam testing. If interference radiation is present,
the measured value switches to fault current for the wait time set
in the device. Overfilling or underfilling cannot be detected during
this time. Even if the LB 480 is very sensitive when it comes to the
detection of interference, one cannot rule out ultimately that spe-
cially low interference radiation influences may not be detected and
the measured value is falsified. For this reason, it is generally nec-
essary that the system operator is informed in advance and appro-
priate measures are taken to maintain the safe operation of the sys-
tem.
7.7 Installation and Wiring
Installation and wiring is described in the relevant operating
instructions.
If necessary, the following inputs can be connected and used:
• Pt100 for temperature compensation
• RS485 for cascading as a multi-detector system
The use of other inputs is not permitted in safety-related applica-
tions.
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