B322 WATER PLANT
PROGRAMMABLE LOGIC CONTROLLER
REQUIREMENTS DOCUMENT
PREPARED BY:
ROBERT SPLINTER, MARK JOHNSON
COMPUTER SCIENCE CORPORATION
FOR:
JUAN ETHERIDGE
NATIONAL AERONAUTICS AND
SPACE ADMINISTRATION
JOHNSON SPACE CENTER
14 JUL 10
2101 NASA PARKWAY
HOUSTON, TEXAS 77058
PLC REQUIREMENTS FOR B322 PLC
July 14, 2010
Rev. A
PURPOSE
1.1 This document is intended to describe the general operating guidelines and the
interconnections required for the Programmable Logic Controller (PLC) that
will be installed in B322 Johnson Space Center (JSC), Houston, Texas.
2 INCLUSIONS
2.1 The following items are included in this document
 Description of System
 Requirements for Operations
 Vendor Requirements
 Appendix A: Wirelists
 Appendix B: Water Tower Technical Data
 Appendix C: PLC and Existing I/O Configuration
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PLC REQUIREMENTS FOR B322 PLC
July 14, 2010
Rev. A
3 DESCRIPTION OF SYSTEM
3.1 The PLC shall provide controls to the four electric booster pumps and their
associated control valves in the B322 Water Plant of JSC. It shall monitor the
status of various water level switches and provide both automatic and manual
start/stop commands to the system booster pumps and associated control
valves.
3.2 The PLC shall provide on/off controls for local street lights located in the
vicinity of B322. Details are provided in Section 4.2.
3.3 The PLC shall provide on/off controls for local water well pumps number
304 and 303. (new)
3.4 The PLC shall provide monitoring for the Johnson Space Center Site Pulse Gas
Meter.
3.5 The PLC shall be a Allen-Bradley Logix5561, Model # 1756-L61, with a
PanelView Plus 1500 touchscreen to communicate data and control the PLC.
Included I/O shall be at least equivalent to the existing I/O. Additional
information is included in Appendix C.
3.6 The PLC shall interface with Honeywell’s Enterprise Building Integrator (EBI),
using MODBUS as the existing communication protocol. Two sets of twisted
pair communication wires are provided. The PLC will also have Ethernet
capability built in.
4 REQUIREMENTS FOR OPERATIONS
4.1
Domestic Water Booster Pump Operation
4.1.1 The PLC shall provide the controls and decision logic as required by this document.
The logic shall be completely contained within the PLC. The PLC shall be operable in
both automatic and manual override modes (operator manual operation).
4.1.2 The PLC shall monitor the points listed in Appendix A. The booster pump start
levels are:
 TD1: 158.8ft
 TD2: 157.1ft
 TD3: 155.7ft
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PLC REQUIREMENTS FOR B322 PLC
July 14, 2010
Rev. A
If the third booster pump remains on for sixty seconds, the PLC shall then issue the
command to start the fourth pump. See Appendix B for more details.
4.1.3 When TD1 closes at 158.8 ft, it will signal the PLC to start a booster pump. The
normal booster pump start sequence is: #1, #4, #2 and #5, but shall be configurable
in the field by a trained operator. The PLC shall look for the following booster pump
start criteria:




A Pump which has electrical power
A pump in AUTO
A pump that is NOT running
The associated control valve must be closed
When it finds a pump that meets all the criteria, it will signal that booster pump to
start and open the associated valve. If a booster pump is not available, it will move
on to the next available pump. If a booster pump meets the above criteria, but does
not start after 20 seconds, the PLC should turn off the failed unit, close the valve, and
attempt to start the next available pump. In manual mode, the operator shall have
full choice of which booster pump to start and valve to open, as long as the above
criteria are satisfied.
4.1.4 A PanelView Plus 1500 touchscreen shall also be provided, and shall provide accurate,
concise information to the operator as to the current status of the electric pumps
and control valves. The display should provide adequate illumination under
existing room lighting. See Appendix C for additional information.
4.1.5 The display shall also provide booster pump and valve selection capability to the
operator.
4.1.6 Examples of Operation
4.1.6.1
For example, if Pump #1 was not in AUTO the PLC would recognize that and go to
Pump #4. If Pump #4 met all the criteria, the PLC would signal it to start. If the
level in the elevated storage tank continued to fall, TD2 would signal the PLC to
start another pump at 157.1 ft. Again the PLC would follow the same sequence and
criteria and start a second pump. When the level falls to 155.7 ft TD3 would signal
the PLC to start a third pump. If TD3 remained energized for 60 seconds, it would
signal to PLC to start another pump. This time the PLC does not consider if the
pump is already running, it will simply signal Pump #5 to start.
4.2 Street Light Operation
4.2.1 The PLC shall also control and monitor the street lights located in the vicinity of
B322. The on/off command is provided by Honeywell’s Enterprise Building
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PLC REQUIREMENTS FOR B322 PLC
July 14, 2010
Rev. A
Integrator (EBI). The PLC will issue the command to the field devices through the
single discrete output and monitor current usage.
4.2.2 The PLC shall provide status and amperage data back to:
 Honeywell via MODBUS and enable capability for Ethernet
 The operator, through the use of the display unit
4.3 Gas Meter Monitoring
4.3.1 The PLC shall monitor the pulse gas meter input, and accumulate gas usage data for
output to:
 Honeywell via MODBUS and enable capability for Ethernet
 The operator, through the use of the display unit
5 VENDOR REQUIREMENTS
The vendor shall provide, as a minimum, the following items:
1) An Allen Bradley PLC, with all associated components and standard accessories,
as listed in Appendix C;
2) A display unit, with all associated components and standard accessories, as listed
in Appendix C;
3) Detailed ladder logic diagrams, showing the relationships between inputs and
outputs;
4) Two copies of the developed software on CD-ROM, along with two hardcopy
printed versions, which are well-commented;
5) Any additional required software or hardware to enable JSC technicians and
engineers access to the PLC hardware or software for future maintenance tasks or
testing;
6) Training for JSC technicians and operators on the new PLC shall be in accordance
with RFQ 09-860, Water Plant Upgrade, B319, Rev. 1.
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PLC REQUIREMENTS FOR B322 PLC
July 14, 2010
Rev. A
APPENDIX A: Wirelist
Discrete I/O:
Microsoft Office
Excel 2003 Worksheet
Analog I/O:
Microsoft Office
Excel 2003 Worksheet
Additional I/O:
Microsoft Office
Excel 2003 Worksheet
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PLC REQUIREMENTS FOR B322 PLC
July 14, 2010
Rev. A
APPENDIX B: Water Tower Technical Data
APPROX
WATER
VOLUME
IN GAL
WATER LEVEL
(x1000).
FEET
HEAD
ABOVE
GROUND
240
163.6
Top of Tank
20.0
100.0
9.00
240
161.6
Probe high level P.T.
20.0
100.0
7.00
240
161.0
System overflows
18.9
93.0
6.50
239
160.8
High Alarm ON
18.4
90.0
6.30
CLOSE
238
160.5
1st boosting mode OFF
17.7
85.0
6.00
OPEN
235
160.0
High Alarm OFF
16.6
79.0
5.50
228
159.0
2nd boosting mode OFF
14.3
64.0
4.50
226
158.8
1st boosting mode ON
13.8
61.0
4.30
218
157.7
3rd boosting mode OFF
11.3
45.5
3.20
214
157.1
2nd boosting mode ON
10.1
38.0
2.67
CLOSE
202
155.7
3rd boosting mode ON
6.9
18.0
1.27
CLOSE
199
155.4
Low Alarm OFF
6.1
7.8
0.93
195
155.0
Low Alarm ON
5.0
6.4
0.44
190
154.6
Probe low level P.T.
4.0
0.0
0.00
OPERATION
mA DC
SIGNAL
PERCENT
OF
TOTAL
(%)
FEET PROBE
SUBMERGED
IN WATER
Page 7 of 8
FALLING
RISING
OPEN
OPEN
CLOSE
OPEN
OPEN
CLOSE
PLC REQUIREMENTS FOR B322 PLC
July 14, 2010
Rev. A
APPENDIX C: Existing I/O and PLC Configuration Tables
MODICON I/O Model #
Description
# of Modules
Total Points
ADU 206
4-point, Voltage/Current Isolated Analog Input Module
4
16
DAP 208
8-point, 24-110 VDC/24-250 VAC Relay Output Module
5
40
DAU 204
4-point, 24 VDC Voltage/Current Analog Output Module
3
12
DEP 216
16-point, 24 VDC Discrete Input Module
2
32
DEP 218
16-point, 155 VAC Discrete Input Module
4
64
I/O
Product Description
MFR
Model #
Quantity
Comments
Logix5561 Processor
Allen Bradley
1756-L61
1
Required
Touchscreen
Allen Bradley
PanelView Plus
1500
1
Required
17 Slot ControlLogix
Chassis
Allen Bradley
1756-A17
TBD
85-265 VAC Redundant
Power Supply
Allen Bradley
1756-PAR2
TBD
CLX Ethernet/IP 10/100
Bridge Module
Allen Bradley
1756-ENBT
1
Required
Analog Input – I/V 8 Pts
Allen Bradley
1756-IF8
TBD
Analog Input
Analog Output – I/V 8Pts
Allen Bradley
1756-OF8
TBD
Analog Ouput
10-30 VAC Input 16 Pts
Allen Bradley
1756-IA16
TBD
Discrete Input, 120VAC
10-30 VAC Output 8 Pts
Allen Bradley
1756-ON8
TBD
Discrete Output 24VAC
4 Slot Rack
Allen Bradley
1771-A1B
TBD
16 Slot Rack
Allen Bradley
1771-A4B
TBD
Power Supply
Allen Bradley
Advanced Interface
Converter
Allen Bradley
A/B 700-HC54Z24-4 Relay
with 700-HN103 Base
Allen Bradley
TBD
1761-NET-AIC
1
TBD
PLC Components
Page 8 of 8
Required