r - The Hong Kong Polytechnic University

Data Triggering and Management Software – Dewesoft 6 Professional Edition, (iii) Analogue-to-Digital (A/D)
Converter – ORION-1624-S1, and (iv) Signal Conditioner – DAQP-LV-S1 for all accelerometer and tiltmeter
data, DAQP- Bridge-A-S1 for all dynamic strain gauge data, DAQP-LV-S2 for propeller type anemometer data,
and PAD-TH8-P for all platinum resistance thermometry type temperature sensor data. Other sensory data such
as ultrasonic anemometers, barometers and rainfall gauges are digital data and therefore no A/D converter and
signal conditioner are required.
3.2.4 Cabling Network System (CNS)
The cabling network system is composed of two categories, i.e., local cabling network system (LCNS) and
global cabling network system (GCNS). The LCNS refers to the cabling network (shield instrumentation
cables – BS 5708 or equivalent) connecting the sensory system (except GPS) and individual DAS. It is used to
transmit the signals received from the sensory system to related DAS. The LCNS for GPS, TMU-5 and video
cameras is single mode fibre optic cables (9/125 μm). The GCNS refers to the single mode fiber optic cabling
networks (with a transmission capacity of 1Gbps) installed inside deck-sections, tower-shafts and pier-shafts. It
is used to collect and transmit the digitized data from the five types of DAS as mentioned above to the DPCS in
the Structural Health Control Room, as shown in Figure 6, located at the Administration Building (or West
Control Building). It is composed of two separated ring-type backbone network (i.e., GCNS-1 and GCNS-2)
with dual-redundancy for data transmission. The GCNS-1 is used for the transmission of all one-dimensional
signals collected from all sensory systems; whereas the GCNS-2 is used solely for the transmission of
two-dimensional (or video signals) collected from the video cameras. Both GCNS-1 and GCNS-2 include
subnets that connect individual DASs and VSCs to the two backbone networks, i.e. GCNS-1 and GCNS-2.
3.2.5 Data Processing and Control System (DPCS)
The data processing and control system is composed of 2 sets of computers, i.e. DPSC1 and DPCS-2. The
former is for the control and operation of the one-dimensional data collected through the GCNS-1; whereas the
latter is for the control and operation of the two-dimensional data collected through the GCNS-2. Each set of
computers is composed of one server and two workstations. The server is 64-bit Itanium server equipped with
two dual-core processors, 128 GB RAM of main memory and 2300 GB hard disk storage system; whereas the
workstation is 64-bit Xeon console equipped with a quad-core processor, 64 GB RAM of main memory, 1500
GB hard disk storage system and a high resolution graphical system. Since the server cannot support high
resolution graphics, the workstations equipped with high resolution graphics are therefore used for analysis and
display of the measured results. The DPCS is devised to carry out four basic functions: (i) control and display of
system operation, (ii) monitoring and display of bridge operation including the early warning of parameters
exceeding the designated performance limit (or at serviceability limit state), (iii) post-processing and analysis of
all measured data, and (iv) dual redundancy for control and display of system and bridge operation. These two
sets of computers are normally referred to as the “SHMS-Server”.
3.2.6 Portable Inspection and Maintenance System (PIMS)
The portable inspection and maintenance system is composed of two Lenovo Thinkpad W700ds Mobile
Workstations and associated maintenance tool-box (including soldering and de-soldering tools) for carrying out
the inspection and maintenance works on the sensory system, data acquisition system, cabling networks. Each
mobile workstation is equipped with customized software tools for detection and rectification of faulty
equipment and facilities.
3.3 Software of SHMS
The software of SHMS is composed of the three major software systems, i.e., (i) the software system for
instrumentation system control and display (customized by LabVIEW software tools), (ii) the software system
for bridge monitoring and display (customized by MATALB software tools), and (iii) the software system for
data interfacing and analysis execution (customized by JAVA software tools). The first and second software
systems are installed and operated in respective DPCS-severs and DPCS-workstations; whereas the third
software system is installed and operated in SHDMS-server. The flow diagram of these three major software
systems is shown in Figure 7. The key issues regarding the customization of these three major software systems
are discussed in the following Paragraphs 3.3.1, 3.3.2 and 3.3.3.
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