ICS Regent+Plus
®
PD-7037
RTD Input Equipment
Input Module, Mux, Termination Panel and Cable
(T7432-IM, T7432-Mux, T7432-TP and T7432-CA)
Issue 1,
The RTD input equipment includes a RTD input module
(T7432-IM), a RTD input multiplexer (T7432-MUX)
termination panel (T7432-TP), and a RTD termination cable
(T7432-CA). This equipment provides terminations and
temperature conversion for as many as 16 RTD inputs,
arranged in 2 groups of eight inputs.
Features
March, 06
, a RTD
·
Sixteen inputs for 100W platinum RTDs.
·
Configuration options:
RTD type:
Input Leads:
Units:
Resolution:
Noise Filter:
·
Complete linearization and automatic calibration.
·
Remote terminations up to 50 cable feet from I/O chas
·
Individual front panel indicators on each module show active,
fault and MUX fault status.
·
2500 volt isolation between Input Module
·
Hot-replaceable input module and Mux.
·
Extensive fault diagnostics.
·
TÜV certified for safety, Risk Class 5.
The input module plugs into an I/O chassis slot and receives
data from the RTD input multiplexer (or Mux). The RTD
input multiplexer plugs into the termination panel and
provides low level signal conditioning, multiplexing, and
American (" = 0.00392 S/S/°C)
European (" = 0.00385 S/S/°C)
2, 3 or 4-wire
Degrees F or degrees C
Units or tenths
50 Hz, 60Hz rejection
and Mux.
sis.
Industrial Control Services
1
RTD Input Equipment
analog-to-digital conversion. The termination panel can be
locat
Each module’s triplicated I/O Safetybus interface ensures that
no failure in the module can affect the operation of the Regent
system or other I/O modules in the system. Extensive fault
detection and annunciation of critical redundant circuits help
prevent the controllers from receiving erroneous data from a
faulty input module. The fault tolerant boundary may be
extended by using three input modules and three
multiplexers. A single RTD can be wired to a single RTD
termination panel which contains three RTD multiplexers for
fault tolerance. The fault tolerant boundary may be further
extended into the process by wiring three separate RTDs, all
measuring the same process parameter, to separate
termination panels, multiplexers and input modules. In
either triplicated configuration, a failed module or multiplexer
can be removed and replaced without interrupting the input
signals.
(T7432)
ed as far as 50 cable feet from the I/O chassis.
Module Operation
A simplified block diagram of the RTD input equipment is
shown i
Two, three, or four-wire RTDs are terminated at the
termination panel. The termination panel routes the RTD
signals to the Mux for multiplexing, signal conditioning, and
A to
termination panel for fault tolerance.
The termination cable connects to the termination panel to
carry RTD data between the input Mux’s and RTD input
modules. A DC-to-DC converter on the input module shares
three power legs from the I/O backplane power and provides
isolated power to the Mux over the termination cable. The
Mux transmits digitized serial RTD data back to the input
module. The maximum allowable cable length is 50 feet.
Sixteen, replaceable current sources on the term panel
provide power to the individual RTDs. These current sources
receive and share power from the one, two or three Mux’s
installed in the termination panel.
n Figure 1.
D conversion. Up to three Mux’s can be installed in the
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Industrial Control Services
RTD Input Equipment
(T7432)
Figure 1. Block Diagram of the RTD Input Equipment.
The Serial data received from the Mux is optically coupled at
the input module to provide electrical isolation. The input
module's 68000-based microcomputer processes the RTD data.
This microcomputer’s functions include:
·
Noise filtering
·
Automatic calibration
·
Temperature conversion and linearization
·
RTD lead-wire compensation
·
Diagnostics
The processor modules send triplicated read data requests to
the RTD input module over the I/O Safetybus. The processors’
addressing data and data read requests are voted by the
module (preventing I/O Safetybus failures upstream from the
module from affecting module operations). The voted result is
then passed to the I/O bus interface logic.
PD-7037
Mar-06
3
RTD Input Equipment
After receiving the voted data read request, the
microcomputer transmits the conditioned temperature data to
the Safetybus interface. This interface places the voted
temperature data onto the triplicated Safetybus bus drivers.
Each of the three bus drivers is independently powered and
controlled (by the I/O transceiver modules) — preventing
failures in a single driver from propagating to the other two
I/O busses. The bus drivers then transmit the data via the
backplane I/O Safetybus to the I/O transceiver modules which,
in turn, transmit the data to the processors.
The RTD input data is packaged as a 16-bit word for each
input. The format of each word is shown in Fi
most significant bit in the word is used as an alarm bit to
indicate an out-of-range RTD input signal. The remaining 15
bits contain signed 15-bit integer data representing the
temperature in degrees C or F and in units or tenths of
degrees, as configured by jumper settings on the Mux.
(T7432)
gure 2. The
Figure 2. RTD Input Data Format.
Testing and Diagnostics
Input Module Testing
Each module’s voter circuits are periodically tested by the
processor modules. Discrepant data are sent through one of
three legs of the I/O Safetybus to determine whether the
module’s voter is able to outvote the incorrect data. A failure
to return the correct majority-voted result to the processors
produces an I/O module error indication at the processor
modules and a module fault indication at the I/O module.
4
Each type of module has a unique identification code that is
read by the controller. This code lets the controller know
which type of module is in
stalled in each I/O chassis slot and
Industrial Control Services
RTD Input Equipment
(T7432)
how to address that module and its points specifically. If a
module is removed, or is replaced with a module of a different
type, the processor modules will indicate an I/O module error.
Loopback logic tests periodically write data to the module and
then read it back to determine whether the module’s I/O bus
interface logic is functioning correctly.
Multiplexer Testing
The serial communications link to the RTD Mux is
continuously monitored. Additionally the data receiv
ed from
the Mux is checked for proper data format, parity and numeric
range reasonableness. The precision voltage references on
the multiplexer are also checked to verify that the power to
the Mux is present and that the voltage references are within
tolerance.
Input Module Front Panel Indicators
Figure 3 shows the physical features of the RTD input
module. The front panel of each module contains status
indicators to display the operational status of the input
module and multiplexer.
Active and Fault Status Indicators
These green and red LEDs indicate the overall health of the
module. During normal operation the green ACTIVE
indicator flashes at the controller's scan rate. If a module
fault occurs the red FAULT indicator turns on and the green
ACTIVE indicator turns off.
PD-7037
Mar-06
MUX Fault Indicator
The red MUX FAULT indicator turns on when any of the
following fault conditions are detected:
·
No data received from the Mux.
·
Corrupted data from the Mux.
·
Unreasonable data values from the Mux.
Failure of the DC-to-DC converter supplying power to the
termination panel or the receiver circuitry can also result in a
MUX fault. Both of these faults are input module faults.
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RTD Input Equipment
(T7432)
6
Figure 3. RTD Input Module.
Industrial Control Services
RTD Input Equipment
(T7432)
Termination Panel and Multiplexer
Figure 4 shows the physical features of the RTD termination
panel and multiplexer. The multiplexer plugs into the
termination panel and is secured in place with two thumb
screws located at each end of the multiplexer. Up to three
multiplexers can be installed in a single termination panel.
Each multiplexer interfaces to a separate RTD input module
installed in an I/O Chassis.
Sixteen current sources are installed on the termination panel
to source current to each RTD. The current sources are
powered from the installed multiplexers and share power
when multiple multiplexers are installed.
Termination cables plug into the DB-9 connectors located to
the right of the three multiplexers. Each cable interfaces one
multiplexer to its associated input module installed in an I/O
chassis.
RTD inputs are wired to the terminal blocks located along the
bottom of the termination panel. Each of the four terminal
blocks has screw terminals for 4 RTD inputs. Four screw
terminals are provided for each RTD input. Two additional
ground terminals on each terminal block are provided to
connect RTD cable shie
ld wires if desired.
PD-7037
Mar-06
RTD Multiplexer Indicators
Each RTD multiplexer has status indicators for power supply
voltages, and transmit data. When positive and negative
supply voltages are present at the termination panel, the + V,
and – V indicators are on. The TX indicator is on when the
Mux is transmitting data to the input module. Normally, all
these green indicators should be on.
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RTD Input Equipment
(T7432)
Figure 4. RTD Termination Panel and Multiplexer.
Application
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Simplex Configuration
A single RTD input module and multiplexer provide a
suitable interface to non-critical input signals. Although
many of the circuits in the RTD input module and multiplexer
are automatically tested and annunciated, some logic circuits
and field-side sensing circuits are simplex and non-tested.
This simplex input configuration is illustrated in Figure 5.
Industrial Control Services
RTD Input Equipment
(T7432)
Figure 5. Simplex RTD Input Configuration.
Fault Tolerant Configurations
For safety-critical inputs, redundant input modules and
multiplexers are used in a 2oo3 or 1oo2 fault tolerant
configuration. In these configurations the redundant RTD
input equipment is connected to single or multiple RTDs.
When single RTDs are installed in the field, the RTDs connect
to one termination panel containing redundant multiplexers
which interface to redundant input modules as illustrated in
Figure 6. When redundant RTDs that sense the same process
variable are installed in the field, each RTD connects to one
termination panel, multiplexer and input module as
illustrated in Figure 7. Each RTD input module, cable, and
multiplexer is hot replaceable. In redundant input
configurations, if a fault occurs in one set of equipment, the
failed equipment can be removed and replaced while the
system continues to sense the inputs from the remaining two
sets of equipment.
PD-7037
Mar-06
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RTD Input Equipment
(T7432)
Figure 6. Fault Tol
erant RTD Input Configuration, Single Sensor.
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Figure 7. Fault Tolerant RTD Input Configuration, Redundant Sensors.
Industrial Control Services
RTD Input Equipment
(T7432)
RTD Multiplexer Configuration
The RTD input multiplexer provides jumpers to configure the
RTD types, noise filtering, temperature units, and
temperature resolution. All RTD configuration jumpers are
located on the component side of the Mux as shown in Figure
8
. The Mux must be removed from the termination pane
l and
the Mux housing disassembled to access the RTD
configuration jumpers. To disassemble the multiplexer,
remove two screws from each end of the multiplexer and
remove the loosened cover.
PD-7037
Figure 8. Location of RTD Configuration Jumpers on Mux.
RTD Type Configuration
Each group of eight inputs, 1-8, and 9-16, is individually
configured for RTD type (American or European) and the
number of wire leads (2, 3, or 4-wire).
Selecting American or European Type
RTDs
To select American type (" = 0.00392 S/S/°C) or European
type RTDs (" = 0.00385 S/S/°C), position the jumper for each
group as shown in Figure 9. The jumper posts are labeled
“JP5” for group 1 inputs (channels 1 to 8) and “JP6” for group
Mar-06
2 inputs (channels 9 to 16).
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Note:
RTD Input Equipment
(T7432)
Figure 9. Selecting American or European Type RTDs.
Selecting 2, 3 or 4-wire RTD Input Lead Config
uration.
To select the lead configuration for the RTDs, position the
jumper for each group as illustrated in Figure 10. The jumper
posts are labeled “JP7” for group 1 inputs and “JP8” for group
2 inputs.
2-wire lead configuration is configured the same as 4-wire lead
configuration.
Figure 10. Selecting 2, 3, or 4-Wire Lead Configuration.
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RTD Current Source
The RTD termination panel has sixteen current sources that
power each o
f the RTD inputs. Termination panels are
provided with standard 1mA current sources. Optionally, 5mA
current sources are available, but must be special ordered.
For most applications, the standard 1mA current sources are
recommended.
Two sets of jumper posts are located on the multiplexer to
indicate the type of current sources installed. These jumper
posts are labeled “JP1” and “JP9” and must be configured for
the same type of current sources. Position the jumper on the
Industrial Control Services
RTD Input Equipment
(T7432)
posts as illustrated in Figure 11 to configure the type of
current sources installed on the termination panel.
Figure 11. Selecting 1mA or 5mA Current Source.
Noise Filtering
RTDs and their associated wiring may be installed in
electrically noisy environments. Noise filtering is required to
ensure that this noise does not affect the reading of the low
level RTD signals. Jumper posts are located on the Mux to
select between 50 Hz or 60 Hz noise filtering.
Choose the frequency which represents the predominant
source of electrical noise in the RTD environment (e.g.
electrical motors). This configuration selection applies to all
16 RTD inputs. The jumper posts for noise filtering are
labeled “JP2”. Position the jumper on the posts as illustrated
in Figure 12 for noise filtering configuration.
PD-7037
Mar-06
Figure 12. Selecting 50 or 60 Hz Noise Filtering.
RTD Data Format
The RTD input module provides linearized temperature data
to the processors in degrees Fahrenheit or Celsius. Jumper
posts are located on the Mux to select between degrees C or F.
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Note:
RTD Input Equipment
Position the jumper on the posts as illustrated in Figure 13 for
the desired temperature units.
The temperature data resolution must also be configured for
units (data increments of 1 degree), or tenths (data increments
of 0.1 degree). Position the jumper on the posts as illustrated
in Figure 13 f
The RTD data is always presented as integer data to the
processor modules. When you select tenths resolution, there
is an implied fixed place decimal before the least significant
digit in the temperature data. For example the temperature
data value 1527 would represent 152.7º.
(T7432)
or the desired data resolution.
The RTD data format selections apply to all 16 RTD inputs.
Figure 13. Selecting RTD Data Format.
The ranges of temperature data for RTDs are shown in
Table 1. When the temperature data is outside the normal
operating range, the NOSIG bit is set.
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Industrial Control Services
RTD Input Equipment
(T7432)
Table 1. Temperature Data Ranges.
Out-of-Range Detection
When the RTD measures temperatures outside of the
operating range listed in Table 1, the signal is considered to
be out-of-range. The RTD equipment will continue to provide
over-range and under-range readings
maximum readings shown in the Table.
up to the minimum and
PD-7037
Mar-06
Also, many open-circuit and short-circuit wiring faults will
cause out-of-range conditions for RTD inputs. In these cases,
the temperature data value is the minimum or maximum
value shown in the Table.
When the signal is out-of-range, the NOSIG bit for the RTD
input is set. In application programming, the NOSIG contact
in ladder logic can be used to sense the RTD out-of-range
condition. For more information, see Programming, starting
on page 23.
Installation Planning
Accuracy Considerations
Use the following guidelines to maximize overall system
accuracy:
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RTD Input Equipment
1. For unused input channels, short the +SENSE, -SENSE,
2. Minimize the resistance of the RTD extension wire by
(T7432)
and -FORCE terminals together. This will eliminate any
floating readings for the unused channels.
using heavier wire gauges. The RTD input circuit supports
a maximum 20 Ohms lead resistance.
Radiated Field Susceptibility
Transmitting equipment should not be o
perated within the
vicinity of the termination panel. Power levels greater than
one watt at a distance of one foot may degrade RTD
measurements and eventually cause a permanent fault to be
logged, resulting in a shutdown (clear to 0) of all inputs on the
affected panel.
Grounding
The termination panel should be connected to the system’s
safety or system ground. Use a minimum of #18 stranded
wire. A chassis ground terminal is provided for this purpose.
It is located at the bottom right corner of the term
panel, near RTD input 16.
ination
Additional ground terminals are provided with each RTD
terminal block group. These terminals are electrically
connected to the chassis and can be used for RTD field cable
shield terminations.
Installing the Termination Panel
16
The RTD termination panel can be mounted in a 19-inch rack
or flush mounted to a panel. Refer to Figure 14 for overall
mounting dimensions for the termination panel and Mux.
Industrial Control Services
RTD Input Equipment
(T7432)
Figure 14. Mounting Dimensions for the RTD Termination Panel.
Termination Panel Cable
The termination panel cable connects a RTD input module to
a RTD multiplexer installed in the termination panel. It
carries power to the Mux and routes serial data to the input
module. One end of the cable has a male DB-9 nine-pin
connector that plugs into one of three connectors on the
termination panel. The opposite end should be cut to the
desired length and wired to the I/O chassis terminal block
immediately above the RTD input module. Do not connect the
shield wire at this end. The six wires in the cable are
connected to the I/O slot terminals as shown in Figure 15.
PD-7037
Mar-06
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RTD Input Equipment
(T7432)
18
Figure 15. Termination Cable Connections.
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RTD Input Equipment
(T7432)
RTD Terminations
RTD wiring is connected to the screw terminals located at the
bottom of the termination panel as shown in Figure 16. When
terminating RTD wiring, follow the recommendations listed
below.
1. Greater accuracy is maintained with a heavier gauge RTD
lead wire. Lead wire resistance should not exceed
20 Ohms.
2. All RTDs within a group of eight must be the same RTD
type (American or European) and use the same number of
leads (2, 3 or 4-wire). 2-wire and 4-wire RTDs can be mixed
in the same group.
3. For unused RTD inputs, short the +SENSE, -SENSE, and
-
FORCE terminals together.
PD-7037
Mar-06
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RTD Input Equipment
(T7432)
20
Figure 16. Wiring RTDs to Termination Panel.
Keying
The I/O chassis can be physically keyed to prevent
accidental
damage caused by inserting a module into a slot wired for a
different module type. Figure 17 illustrates how the slot keys
are installed on the I/O chassis slot field wiring connectors.
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RTD Input Equipment
Module
Upper
Connector
Lower
Connector
T7432
15 15
(T7432)
The slot key positions for the RTD input module is listed in
Table 2.
PD-7037
Mar-06
Figure 17. Installing Slot Keys.
Table 2. Slot Key Positions.
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RTD Input Equipment
(T7432)
Configuration
E
ach input module is configured using the
W
INTERPRET
I/O
Configuration Editor. In the editor, you will perform the
three steps described below to configure the input module.
1) Set the Module Type:
Position the cursor on the module slot you wish to define.
Choose Set Module Type from the Edit Menu and select
the RTD input module from the list.
2) Edit the Module Definition:
Choose Edit Module Definition from the Edit Menu. A
dialog box will open where you can define the input point
definitions.
22
Figure 18
3) Edit each point:
. RTD Input Module Definition.
Position the cursor on a Point definition and choose Edit
from the Module Definition dialog box to define a name
and description for each input point. In the RTD Input
Point dialog, enter a tag name (up to 12 characters) and a
description (up to 40 characters). The tag names are used
in the application program to represent the value of the
RTD input in your control algorithms and interlocks. The
input data is in the units and format as configured on the
RTD Mux. For more information, see RTD Multiplexer
Configuration, starting on page 11.
Industrial Control Services
RTD Input Equipment
Note:
(T7432)
Figure 19. Defining a RTD Input Point.
Programming
Inputs are referenced in the application program through the
tag names defined in the I/O Configuration Editor. The RTD
inputs variables will be in the engineering units (degrees F or
C) and resolution (1 or 0.1 degree) as configured on the RTD
multiplexer. Because the input data is already represented in
engin
variables in the application program.
eering units, there is no need to scale the RTD input
The MSB of each RTD input represents out-of-range (or
NOSIG) status. This bit is normally equal to one. When RTD
inputs are used in application program instructions, this MSB
is masked and the sign bit is shifted to the MSB. This allows
the application program instructions to evaluate only the data
portion of the temperature value. This is true for all
application program instructions except Block Move (in
ladder
logic). The Block Move instruction moves the entire word of
data without masking off the NOSIG bit.
PD-7037
Mar-06
Programming Fault Tolerant RTD Inputs
To program fault tolerant configurations using triplicated
RTD input modules, a midvalue element can be used as shown
in Figure 20.
Figure 20. Programming Fault Tolerant RTD Inputs.
23
RTD Input Equipment
In this illustration, VALUE_A_NAME, VALUE_B_NAME,
and VALUE_C_NAME represent the three RTD inputs to be
mid-value selected. ERROR_A_NAME, ERROR_B_NAME
and ERROR_C_NAME are the error bits for the RTD inputs.
RESULT_NAME is the result of the mid-value instruction.
The field Limit is the integer value, in similar units to the
Value A, B and C variables, that a RTD input can deviate
from the mid-value result before signaling an error (via the
Error A, B or C bits). Once an error bit is set, it is latched.
RESET_NAME is the reset bit used to reset the latched error
bits.
(T7432)
RTD Signal Out of Range Conditions
The NOSIG contact in ladder logic function blocks can be used
to detect an out of range RTD input signal. The NOSIG
contact will be true when the RTD input signal is outside the
normal operation limits (see Table 1, Temperature Data
Maintenance
Ranges).
Calibration
The Mux contains an ultra-stable voltage reference circuit for
auto-calibration of all RTD channels. This circuit does not
require re-adjustment.
Safety Considerations
The RTD input modules are TÜV certified as non-interfering
and can be used for non-safety critical inputs in Risk Class 5
safety applications.
24
The RTD input equipment is TÜV certified as non-interfering
and when properly configured is also certified for Risk Class 5
safety critical inputs. Safety critical configurations include
redundant input modules and multiplexers and application
programmed midvalue selection methods.
Redundant RTDs can be used with redundant input modules,
termination panels and multiplexers to eliminate any single
Industrial Control Services
RTD Input Equipment
Safetybus Power
1.8 load units
Number of Inputs
16, two, three, or four-wire
RTDs
RTD Input Types
American:
European:
100W Platinum
"
= 0.00392 S/S/
°C
"
= 0.00385 S/S/
°C
RTD Units
Degrees Centigrade or
deg
rees Fahrenheit
RTD Resolution
Tenths or units
RTD Temperature Range
Normal Operation:
Over-Range:
Under-Range:
-
200° to +800° C
(-
328° to +1470° F)
+801° to +883° C
(+1471° to +1622° F)
-
242° to -201° C
(-
404° to --329° F)
In
put Resolution
14-bit, 1 part in 16,384
Response Time
2 seconds, typical
Linearization
Automatic
Calibration
Automatic
Maximum Lead Resistance
20 ohms
Current Source
1 mA (standard)
5 mA (optional)
Accuracy
T < 93
°
C (200° F)
T > 93
°
C (200° F)
+/- 0.55° C (1.0° F)
+/- 1.1° C (2.0° F)
(T7432)
points of failure and extend fault tolerance to include the
RTDs.
For additional safety considerations, please refer to the Safety
Considerations section of the Regent User’s Guide.
Specifications
PD-7037
Mar-06
25
Common Mode Rejection
100 dB @ 50/60 Hz
60 dB minimum, elsewhere
Normal Mode Rejection
70 dB typical
Termination Panel Cable Length
Maximum 50 cable feet
(15 m)
Isolation
2500 volts minimum (Mux to
input module)
Operating Temperature
0°
to 60° C
(32° to 140° F)
Storage Temperature
-40°
to 85° C
(-40°
to 185° F)
Operating Humidity
0 to 95% rela
tive humidity,
non-condensing
Safety
Pending certification to DIN
V VDE 0801 for Risk Class 5.
Also designed to meet UL
508 and CSA 22.2, No. 142
-
M1981
Heat Dissipation
Input module:
Termination panel/Mux:
4.5 Watts, 15 BTUs/hour
2.5 Watts, 9 BTUs/hour
Dimensions
Input Module
Height:
Width:
Depth:
Termination Panel
Height:
Width:
Depth (with MUX):
12.6” (320 mm)
1.27” (32 mm)
10.125” (257 mm)
6.94” (176 mm)
19.0” (483 mm)
5.12” (130 mm)
Weight
Input module:
Mux:
Termination panel:
3.5 lbs (1.6 kg)
2 lbs (0.9 kg)
5.6 lbs (2.5 kg)
RTD Input Equipment
(T7432)
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