Supervisory Control and Data Acquisition (SCADA) Systems are frequently used in
Water and Waste Water Systems to monitor and control tank levels, remote well pumps, lift station pumps, high service pumps, valves, and chemical pumps.
SCADA Systems monitor a variety of plant data including flows, motor currents, temperatures, water levels, voltages, and pressures. Alarms at central or remote sites triggered by any abnormal conditions are propagated to the HMI computer for operator's attention. In addition to alarms, important plant information such as, levels, flows, pressure will be logged in the HMI computer database for reports and trends.
We have thousands of active remote telemetry sites monitoring and controlling equipment via radio, telephone, and cellular systems. We manufacture a complete line of RTU's, CTU's, and control components. We handle the complete system: from the central computer and software to the pump controls and treatment plants.
The SCADA Communication network is spread throughout the water distribution system
to monitor parameters such as tank levels and system pressure.
Workstations, which are typically PC-based and located in a control or
operations room at a treatment plant,
allow operators to view the entire process and perform control actions.
With in the plant, process controllers or programmable logic controllers (PLC's) supervise unit processes, such as chemical treatment, sedimentation, and filtration. A local area network (LAN), such as Ethernet, links the controllers to the workstations as well as to one another.
Based on the type of water treatment plant, surface water treatment vs. a well system, the automation process can get quite involved. Control Systems has done countless jobs of both types.
Our systems are far superior to others. We have done surface water treatment plants that involve drawing water from river, filter the raw water using bar screens, then enters sedimentation where water is mixed with various chemicals to get the dirt out of the water then the settled water is fed through the filters and to the clearwells. Various chemicals are mixed at various stages of the process.
Our systems provide the operator with the luxury of backwashing the filters automatically based on the hours it is in service or based on the amount flow that has been through the filter.
In a well based water treatment plant, we provide the operator with a host control matrix system that allows him to designate a tank as a controlling tank and all the wells should run or stop based on the level in that tank. Wells can be grouped and a group of wells can be started and stopped from the HMI computer by the operator with the click of a button or by the selected tank. Well groups can be alternated based on first-on-first-off or all stop algorithms. Our graphics are very easy to understand by the operator with minimal computer skills and knowledge of the water treatment process.
Control Systems has done quite a number of waste water treatment plants including sequential batch reactor based, traditional lagoon based, and clarifier based. We have done it all. We measure all the parameters at each step of the way, process the parameters based on the set criteria by the operators, and control the process 24x7. We generate alarms appropriately and inform the operator of any abnormal conditions in the system via a dialer or on the HMI system.
Control Systems Duplex Controller DC201B combines duplex controls with a built-in Lift-Station Analyzer, Remote Telemetry Unit and optional data logging capability. The controller normally operates on 120 VAC but can also operate on +12 VDC. The controller is panel mounted with a separate backplate mounted terminal board for field contacts.
Automatic motor alternation is provided along with Manual/Off/Auto switches for each motor and a Lead-Pump selector switch. Variable time delays are provided for motor failures. Alarm indicators and outputs are provided for motor failure, seal failure, high level and auxiliary alarms. All inputs are optically isolated and operate on +15 VDC.
Integral RTU functions and optional Float Test (FT201) and Alarm Telemetry boards (DCAT-E) make this a very versatile system.
Remote Telemetry features include industry standard communications protocols, user-selectable unit number and baud rate, and RS232 and RS485 serial ports for interfacing to System Control and Data Acquisition (SCADA) systems via telephone or radio modems. A Dallas Semiconductor ‘1-wire’ communications option board may be added for communications to I-button security badges. An optional LCD operator interface can also be used for stand-alone units or for temporarily viewing statistics locally. Four (4-20ma dc) analog inputs are standard for RTU transmission: one for tank level and three others for any desired input to the SCADA system.
This multifunctional unit also includes CSI’s Lift-Station Analyzer algorithms which track vital duplex lift-station statistics including influent flow rate estimation and totalized flow, water level, pump runtimes and capacities, which are calculated on each fill and draw down cycle.
Graphical display screens indicating status of pump stations. A pump station screen
typically show the instantaneous station flow, wet well level for waste water pump stations, pump run times, pump starts, pump status such as running, failed, off,
forced on and forced off, pump start position, power status, generator status etc.
For Variable Frequency Drive (VFD) pumps, the screen also shows VFD speed and other VFD setpoints.
An elevated storage tank automation typically involves taking the water tank level
via 4-20 ma analog input using submersible level transducer and controlling well pump(s) to fill the tank as needed. The operator
can enter well start and stop setpoint via a locally installed operator interface (OIT) or remotely from the SCADA computer.
He can also enter tank low water level alarm and tank high water level alarm setpoints. The RTU at the tank site reads inputs and controls the outputs by calling the well pumps based on the set setpoints. If the water level in the tank crosses the alarm conditions then an alarm is generated appropriately and operator will be informed via a dialer, If one is available or on a SCADA System.
In a multiple well system, operator can enter lead well start and stop setpoint and lag well start and stop setpoint. When the level drops below lead well start setpoint, the tank controller calls for the lead well pump to run. If the level reaches stop setpoint, lead well will be stopped. On the other hand, upon calling the lead well, if the level continue to drop and reaches below lag well start setpoint, lag well will be called to run. Both well pumps continue to run until the tank level reaches stop setpoint, at which both well pumps will be turned off.
A well automation involves reading the inputs such as flow, pressure, motor current and optional chemical residuals, well switch status, Hand-Off-Automatic,
calculating statistics such as pump starts, runtimes, controlling
outputs to run the well pump, optional chemical pumps. Each well RTU has
setpoints to for generating high and low alarms for high flow, low flow,
high pressure, low pressure, high current, and low current alarms. It
also generates pump failure alarm
if the pump failed to run in a set period of time after being told to run.
In the event of a communication failure with the tank, our RTU runs a smart internal algorithm that turns on and off the well pump to prevent the tank from running empty. If interested, call us for more on this.
In addition to its local operation, the RTU is responsible for communicating its state to the SCADA system computer, if available.
SCADA shall display process and systems alarms read from data concentrator or the network. Each of
these alarms shall be prioritized in the SCADA as per their importance. For example, high wet well level or station power failure
shall have highest priority. Alarm screen shall have button for operator to acknowledge alarms.
Active, inactive, acknowledged and unacknowledged alarms shall be identified with different colors.
Our HMI systems come with the following features:
* Overview screen showing the overall status of the system
* Tank screen for each tank in the system that shows level, setpoints, and active alarms * Well screen for each well in the system that shows flow, motor current, pressure, H-O-A switch position, well run status, alarms, daily statistics, and alarm setpoints
* Clearwell or Reservoir screen with the level, low level lock out setpoint, service pump statuses, daily statistics
* Lift station screen with pump statuses, H-O-A switch statuses, motor current when running, daily statistics, alarm setpoints, and alarms
* A map screen showing the physical locations of all the sites in the system with navigation to the site with a mouse click
* An alarm summary screen showing all the acknowledged in-alarms, unacknowledged in-alarms
* An alarm history screen with selectable start and end date
* An activity screen showing all the secured actions performed by the various users
* An activity history screen with selectable start and end date
* A trend screen for each important analog parameter such as, level, current, flow, etc showing the real-time and historical data with timeline
* A report package.
Our SCADA systems come with a report package that can be used
to generate daily, weekly, and monthly reports of all the sites or selected sites for selected period.
Reports can also configured for automatic printing, faxing, and e-mailing.
We store all important SCADA systems parameters such as, Flow, Pressure, Level,
Motor Current, Chemical Dosages, Well/Pump Running etc for historical trending.
We provide easy navigation between different trends and other parts of the system.