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Siemens Building Technologies
Basic Documentation LMU54... / LMU64...
CC1P7494en
HVAC Products
5 Clip-in module OCI420... for communication via LPB
07.11.2002
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.
Priority
Status
OCI bus
power supply
LED status indication
1
OCI not configured
Optional
ON
2
OCI and LMU incompatible
Optional
7%
93%
Frequency: 1 Hz
3
OCI configured
LPB short-circuit or no power
Optional
OFF
4
LPB address inadmissible
Optional
7%
93%
Frequency: 1 Hz
5
OCI configured
LPB ok
Off
5%
95%
Frequency: 1 Hz
On
5%
20%
5%
70%
Frequency: 1 Hz
In addition, the interface generates the following error messages of its own:
Error code
(display on the RVA or
on operating section of
the LMU)
Cause of error
Troubleshooting
81
Ø
Physical defect of bus line
(short-circuit / open-circuit)
Ø
Bus power supply switched off
at several units
Ø
Replace bus line or search for disruptions
and short-circuits
Ø
Activate automatic bus power supply at all
units (LMU parameter «LPBKo nfig0», no.
17)
82
Ø
2 or more bus users have the
same segment and device
address
Ø
Check the set segment and device address
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)
100
Ø
2 or more units in the system
are configured as time master
Ø
Check the selected behavior or the clock
time. Configure one single unit in the
system as the clock time master. Also refer
to «Uniform system time »
140
Ø
The set segment and device
address does not match the
configured plant diagram
Ø
For cascade applications, diagrams 80
through 85 apply. Segment address = 0;
device address 2...16
Ø
For zone extensions, diagrams 64 through
76 apply. Segment address = 0; device
address = 1
1)
A faster response of the entire system can be obtained by cutting the power supply
for a short moment
