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Schneider Electric Application Examples

Off-shore oil platforms communicate using Data-Linc wireless serial modems interfaced with Modicon PLCs

In order to more effectively utilize their resources, two competing oil companies wanted to share an oil pipeline between their two offshore platforms two miles apart off the coast of California. Because the shared pipe traversed the ocean floor six hundred feet below the surface, it was crucial to monitor this pipe and its contents very closely. Since the companies needed to share pipeline data in a timely manner without laying cable, Data-Linc SRM6000 frequency hopping spread spectrum license-free radio modems were selected to interface with Modicon PLCs. Read complete article with diagram.

Sussex County SCADA upgrade: Modernization without compromise

Delaware— Modernization in any business can be a consuming project. Sussex County’s water/waste water facility, consisting of over 350 sites, decided to upgrade their SCADA (Supervisory Control and Data Acquisition) system due to operational demands. These demands included an increase in data acquisition capabilities and overall modernization. Read complete article with diagram.

SRM6100 Wireless Serial Radio Modems Revamp Operations in a Power Generation Plant in China

Serial radio modem Coal Power Generation Plant application in China
Mounted antenna (in forground) allows modems to transmit data between central control and ship-side coal unload manchines 350-500 meters away.
A power generation plant's coal-unload system that became operational in August of 1996 in China was brought into the 21st century by a recent revamping of the system. A Modicon-987/785E PLC and supervisor PC provide the control and monitoring while another PLC operates in the unload machine driver room. Ten mobile coal-unloaded machines work on ships during the coal handling process. Since 1996 coal-unload machines communicated with the control room through a slide wire with limited data transfer. Not only was data communication limited, but the slide wire was costly, difficult to maintain requiring continual maintenance for optimal performance. The revamped system utilizes Data-Linc's SRM6100 wireless serial radio modems which eliminate the need for costly slide wire.

wireless serial RF modem Power Generation Plant application in China
SRM6000 wall mount in plant control room
Since the update the operator can read the parameters, movements and operations of the individual remote coal-unload machines and send control commands to them. Maintenance personnel in the control room can change the program on the remote PLC at the unload machine; additional PCs in the control room can share data from the unload machines; the PLCs have the capability to receive control and program commands from the control room; and if the primary PC (PC1) has problems, a switching circuit switches the SRM6100 wireless modem to another PC, ensuring the RF communication between control room and coal-unload machines.

FSK Wire and Spread Spectrum Radio Modems in a Typical Water District Installation

The City of Enid, Oklahoma Water Production Department has 150 water wells, two treatment plants, three raw water booster plants and 30 million gallons of storage capacity for treated water. The City maintains 200 miles of raw water gathering lines located in three counties. The average daily use of treated water is 10 million gallons. City water wells can produce 25 million gallons of untreated water per day, although peak usage in the summer rarely exceeds 17 million gallons. The treatment plants can treat up to 40 million gallons per day.

In 1991, electric usage exceeded $500,000. Ways to reduce power cost were sought. Each well and plant was surveyed to find out which wells, plants, pumps, etc. were most efficient. A well rehabilitation program was then instituted and a SCADA System with VFDs (Variable Frequency Drives) was selected consistent with particular attention to managing a sensitive aquifer.

The first leg of the project was to automate the newest well fields to be operated from the Enid plant. Cleo Springs (35 miles from Enid plat) and Ringwood (30 miles from Enid plant) each consist of approximately 30 wells and a pumping station. They are setup so the operator can start/stop each well from each plant over an in-place cable system.

Cleo springs, with the longest distance (7 miles) between plant and well, was targeted first. Following the selection of PLC communications from plant to well on the existing cable system had to be worked out. The particular Modicon 984 Series PLC chosen did not support half duplex communications with the programming software, so a communications medium had to be found to support two wire 9600 baud full duplex data communication at a distance of 7 miles on 19 gauge solid wire. This was a rather daunting task. Data-Linc MDL500 FSK wire modems were the only equipment located capable of meeting this challenge.

After installation of a Variable Frequency Drive, PLC and a computer with automation and control software at the Cleo Springs and Enid plant, both plants could be operated from Enid via phone line. At Plant 2 in Enid, approximately four miles from the main plant, a PLC and VFD was installed to maintain minimal tower level at 60 psi. A continual decrease in the tower level will increase effluent pressure. If VFD rpm reaches 100 percent for a set time period, the backup pump will engage. When rpm drops below the set point for a specific time period, the backup pump will shut down, and when the tower level increases, pressure will return to 60 psi.

The savings to date over a four period as a result of installation of the new SCADA system has amounted to well over $400,000. Work is now underway on an upgrade to a 32 bit operating system as well as improvements to the SCADA software. All remote plants will be linked together with a Data-Linc SRM6000 902-928 MHz spread spectrum radio system to avoid the long distance calling currently required.

Other Typical Industry Applications

wire modems in Quantum and Compact 984-120 rack mount chassis enclosures

Rack mount versions of Data-Linc modems including spread spectrum radio, dial-up and FSK wire modems housed in Quantum and Compact 984 enclosures. Data-Linc stand-alone metal enclosure with mounting flanges also shown.

Remote Camera Control

A petroleum company in Texas uses Data-Linc's SRM6200E wireless Ethernet modem with Modicon PLCs to monitor alarms, then control a remote camera to view the alarm site. (For more video applications, see Security in the Industries section of our web site.)

Miller Brewing Company

Crane control application using Data-Linc SRM6000 Frequency Hopping Spread Spectrum Radio Modems (no site license required) communicating between a Modicon 984 Master and Modicon Compact 984 Remote units running Modbus ASCII on the Modbus Port.

Washington State Department of Transportation

Over 40 Data-Linc LLM1000 Leased Lines FSK Modems utilized with Square D SY/MAX PLCs to extend their I/O distance capabilities. Many single outputs are multi-dropped several hundred feet apart to provide traffic control at electronic signs leading to a freeway tunnel.

British Petroleum (BP Exploration)

Full duplex 9600 baud data communications between Modicon Compact 984 PLCs at several well heads and the control trailer using Data-Linc MDL500, DOVE (Data Over Voice Encoder) and LCM100 Power Line Modems with PLI500 Power Line Isolators to transmit data over existing spare pair and superimposed on in-place 480 VAC wiring. The multi-drop connection between DOVEs and LCMs utilizes Data-Linc's AE-485 Auto Enable technology (compatible with RS 485) to allow half duplex operation without the need for enable lines or signals.

City of Enid Oklahoma Water Production Department

SCADA installation monitoring tank/well levels and controlling pumps at up to 34 miles using Data-Linc full duplex 115.2 Kbaud SRM6000 spread spectrum radio modems and 9600 baud MDL500 FSK wire modems communicating between computers and Modicon 984 PLCs.

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