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City of Philadelphia Wastewater Management
Data & Design has developed various packages involving embedded
systems, and windows interfaces, including a PLC interface for the
City of Philadelphia's water department. The system was designed to
replace a Wonderware Factory Link application. This software could
be customized to fit any city's requirements.
The system monitors and controls the flow of waste water. Consisting
of a Windows NT 4 server utilizing raid level 5 running on SQL
Server 7.0, a data collection computer with a digi-board which
interfaces with 16 modems is used to call the PLCs located at
approximately 260 sites throughout the city of Philadelphia. The
computer calls the sites, triggering the sites to call in alarms in
real time.
A Data Concentrator server was written in VC++ and calls the Modicon
PLCs using a bank of 16 modems. This multithreaded application uses
a Modbus protocol, collects all the information and stores it in a
SQL server database. The information is then used for trending,
reporting and alarms.
The MMI interface is written in VC++, and replaces an older Factory
Link application. Visual C++, Visual Basic and Crystal Reports were
utilized, with Access and SQL Server as the databases. Sockets were
used to develop the real time portion of the system, which transmits
the information to the client computers. This gives the field crews
the ability to watch the activity in real time to aide in
troubleshooting. Prototypes were developed to demonstrate how to
upgrade the present system using Microsoft Net technologies as well
as a PocketPC interface. This would allow the field crew to use a
pocket pc equipped with a modem to view all the information
available to the computer system. The Net technologies provide a
means for the data to be available to the city through the intranet.