Transcript DPC Maintenance

DP Cabinet
DP Cabinet
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The DPC 21 (Dynamic Position
Cabinet) comprises two identical
computer, each with its I/O System.
The cabinet comprises two areas:
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Process cabinet
Termination cabinet
DPC Cabinet
Process Cabinet
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Inside we will found the power
supply, that provides a conversion
from 220/230 Vac to 24 Vdc. This
voltage will be distributed in the
process cabinet.
In the process cabinet each “user”
is protected with a fuse.
Process Cabinet
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A filtering system is installed before
the AC/DC conversion to prevent
current spikes and environmental
disturbs.
Process Cabinet
Process Cabinet
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The Process cabinet comprises two
card-rack, filled with the I/O
interfaces.
Each card-rack contains a BP-407S
backplane which provides
connectors for cards and cables.
Process Cabinet
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The normal configuration for the
card-rack comprises the following
I/O cards.
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DI 400 (32 digital input channels)
AI 400 (32 analogue input channels)
AOV 406 (26 analogue input and 6
analogue output channels)
Process Cabinet
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The serial line interface unit (TBSS)
is used with up to two plug-in unit
installed on it.
Each unit can handle the RS-232,
the RS-422 and the current loop
protocol.
Process Cabinet
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In a dual redundant system the
thrusters are grouped into two
independent groups.
Each computer has two AOV-406,
one for each group, in order to
make the correct I/O signals.
SBC 500
The Single Board
Computer 500 is a
real time computer
for control process
purpose, based on
the Motorola
MPC755 RISC
processor at 300
MHz.
SBC 500
The SBC 500
perform the main
task of DP system,
included the
Vessel Model. In
the DP OS only the
GUI is executed.
SBC 500
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The SBC 500 main bus is the PBUS
(Process BUS), also called PBUS2 on
the new versions.
Four alarm are provided:
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Power under voltage
Fan not running
High Temperature
WatchDog timeout
SBC 500
The front panel
provides the
following
functions:
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Reset
NMI
Mode
RS-232 Console
LED Indicators
AI-400
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The AI-400 is an interface between
the PBUS2 and 32 analogue inputs.
The input range is ± 10 Vdc
Each input is provided by a low pass
filter
There are no configurable parts on
the AI 400 card.
AI-400
Can receive up to 32 voltage signals from the field. It lowpass filters the signals and then guides them one at the
time through the Analogue Multiplexers for A/D
conversion.
When the SBC performs a read-channel-x instruction and the
card address comparator in the PLD respond with ‘match’,
the channel x value is multiplexed through the Analogue
Multiplexers, A/D converted and enebled to the bus as a
16 bit word through the Output data buffer to the PBUS2.
The SBC reads one value at the time from AI 400 by
addressing the card and one specific card device. The card
device can either be one of the 32 channels or one of
several registers in the Register and Control Logic PLD.
DI-400
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The DI-400 is an interface between the
PBUS2 and 32 digital inputs. It low-pass
filters the signals and saves them in two
16 bit registers on the card.
An optocoupler is included for each
channel to isolate the field and the SBC
side from each other.
There are no configurable parts on the DI
400 card.
AOV-406
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The AOV 406 card is an interface
between the Process Bus (PBUS2),
and 26 single-ended analogue input
and 6 single-ended analogue output
channels.
AOV-406 - Fail-safe outputs
The fail-safe mechanism has two levels for this card. They
are:
• If contact with the SBC is lost, but the card itself
functions OK, the PLD watch dog is triggered and forces
the fail-safe values initially programmed to be set out by
the micro-controller.
The fail-safe values may be programmed for each
channel and can be:
- the last received and accepted values from the SBC.
- 0 Vdc.
• If the refresh mechanism on the card is defect, the refresh
watch dog opens the analogue switches and set all
outputs to 0 Vdc.
AOV-406 Configuration
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The DIP-switch S1 bit 1, 2 and 3
are used to set the operational
mode of the card. Bit 4 of the DIPswitch is not used.
OK/error indication
AI 400 – DI 400 – AOV 406
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A bi-colour (red/green) LED on the front of the
card indicates the status of the card. A watch
dog, controlled from the SBC, drives the LED.
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Green light indicates that the SBC sends modulealive messages to the card. This means that the
SBC can see no error with this card. In a system
with no errors all the I/O card LEDs light green.
Red light indicates that the card is not running in
the system. The reason for the red light can be:
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the SBC has stopped.
the watch dog on the card has timed out.
the SBC has discovered a self diagnostics error on
the I/O card and sends a module error messages to
it that turns on the red LED.