Siemens LMU54 Series Basic Documentation page 87

Priority
Error code
(display on the RVA or
on operating section of
Siemens Building Technologies
HVAC Products
In addition to transmitting error codes, the OCI420... features status indication by means
of an LED. That LED indicates the state of the LPB and interface.
Status
1 OCI not configured
2 OCI and LMU incompatible
OCI configured
3
LPB short-circuit or no power
4 LPB address inadmissible
OCI configured
5
LPB ok
In addition, the interface generates the following error messages of its own:
the LMU)
Ø Physical defect of bus line
(short-circuit / open-circuit)
81
Ø Bus power supply switched off
at several units
Ø 2 or more bus users have the
82 same segment and device
address
Ø 2 or more units in the system
100
are configured as time master
Ø The set segment and device
address does not match the
140
configured plant diagram
1)
A faster response of the entire system can be obtained by cutting the power supply
for a short moment
Basic Documentation LMU54... / LMU64...
5 Clip-in module OCI420... for communication via LPB
OCI bus
power supply
Optional
Optional
Optional
Optional
Off
On
Cause of error
Ø Replace bus line or search for disruptions
Ø Activate automatic bus power supply at all
Ø Check the set segment and device address
Ø Check the selected behavior or the clock
Ø For cascade applications, diagrams 80
Ø For zone extensions, diagrams 64 through
LED status indication
ON
93%
Frequency: 1 Hz
OFF
93%
Frequency: 1 Hz
95%
Frequency: 1 Hz
70%
Frequency: 1 Hz
Troubleshooting
and short-circuits
units (LMU parameter «LPBKo nfig0», no.
17)
at all units and, if necessary, make
changes according to «Setting the LPB
device and segment address»
Note: After rectification, the error can still be
present for up to 11 minutes 1)
time. Configure one single unit in the
system as the clock time master. Also refer
to «Uniform system time »
through 85 apply. Segment address = 0;
device address 2...16
76 apply. Segment address = 0; device
address = 1
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CC1P7494en
07.11.2002