Feature Story
(Issue 8, 2007)
Applications: End User, System Integrator, and OEM
Poultry farm utilizes PLC control to increase efficiency
by TJ Johns,
Senior Editor
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In the New England town of Monroe, New Hampshire, you’ll find picturesque settings filled with family-owned dairy and poultry farms. Situated in the Connecticut River valley at the edge of the White Mountain National Forest is a poultry farm, called Pete and Gerry’s Organics, with something to crow about. Pete and Gerry’s Organics has found a way to increase efficiency and productivity by using automation to help gather and process eggs.
It all started around 1950, when Les Ward, a retired World War II dive bomber, decided to set up a poultry farm using just a few hundred hens. In the late 1960’s his brother-in-law, Rodney Stanton, joined him to manage production for the New England area. The business focus was on quality and freshness.
In 1997, the business was passed down to Rodney’s son, Pete Stanton, and Les’ son-in-law, Gerry Laflamme.
Continuing the tradition of quality and freshness, Pete and Gerry developed high standards of their own. They wanted totally organic eggs, free from antibiotics, medication, hormones, pesticides, or animal byproducts, to be distributed throughout New England.
Today, after four generations, this small family farm boasts six barns, each over 400 feet long, and nearly 110,000 Hy-line Brown cage-free hens. The hens are a hybrid cross between a Rhode Island Red and a White Leghorn. Each hen is capable of laying up to 320 eggs per year.
A cage-free environment allows the hens to roam freely inside the barn. When they are ready to lay their eggs, the hens climb into red nesting boxes, which tilt back slightly. As each egg is layed, it gently rolls out of the nest and travels on a series of conveyor belts that transport it to the processing facility.
Originally, workers had to start and stop the conveyors manually to control the egg flow. Flow management was difficult, and the process labor intensive; only one barn could be completed at a time. With an average egg production of 80,000-90,000 eggs per day, Pete and Gerry were looking for a way to increase efficiency and minimize human error.
Gerry’s son, Jesse Laflamme, joined the family business after graduating from Bates College and serves as co-owner and general operations manager. In efforts to increase both efficiency and productivity, Jesse decided to fully automate the barns and processing building.
With no formal training in industrial controls, Jesse relied on advice from AutomationDirect’s technical support team and referenced their product manuals to develop a control system for egg collection and transport. Happy with the overall experience, Jesse states, “The tech support is just fantastic. They are a huge help. If I find a problem on our farm that I have a hunch automation equipment can help us with, I just start reading the books, call up tech support, or look through the catalog and see what products are available, and pretty soon I’ve got a solution.”
Using products from AutomationDirect, Jesse configured PLCs, Marathon motors, GS1 inverters and analog diffuse proximity sensors to control the egg flow.
With the new system, once the egg rolls from the nest onto the gathering conveyor, it is transported to a cross conveyor. Here it begins its journey from the barn to the main transport conveyor, which takes the eggs to the processing building. As the eggs load onto the cross conveyor, proximity sensors send a 0-10 volt signal representing egg volume to a DirectLOGIC D0-05DR PLC. An inverter receives a signal from the PLC and adjusts the gathering conveyor’s motor speed as the egg flow increases or decreases.
This has helped increase efficiency, because, according to Jesse, “having this system in all of our barns has allowed us to run all the barns at the same time. Essentially, the barns are controlling their own flow. We’re able to blend all the egg production together, which is a big plus.”
Jesse also equipped the PLC with a D0-01MC memory cartridge that supports a real time clock. Each barn relies on the PLC to advance the gathering conveyors every 15 minutes during less productive periods to prevent the build-up of eggs.
In each barn, where the cross conveyors join with the main transport conveyor, Jesse uses two analog diffuse proximity sensors to send signals to the PLC. The two signals are averaged and a 0-10 volt signal is sent to an inverter to adjust the cross conveyor speed accordingly.
The speed of the main transport conveyor leading from the barns into the processing facility is controlled by a 3/4 hp motor and GS2 inverter receiving commands from a DirectLOGIC D0-06DR PLC .
As the eggs from all six barns enter the processing facility, Jesse enlists the help of the D0-06DR PLC to control an accumulator table fitted with more sensors. Signals from these sensors are sent to the PLC, averaged, and used to control the proper start and stop sequence of the main transport conveyor from the barns.
Within the processing building, equipment output is set based on cases per hour. In the past, the only way to precisely know the production rates was to print out reports and throw in some mathematical calculations during the process. This was very time consuming. Jesse explains, “That’s obviously eating away at your actual cases per hour. Even at the end of the day, there’s no real report that tells you what your actual cases per hour are, and certainly nothing in real time.”
When the machine puts a set number of eggs into a carton, a signal is sent to the PLC. The PLC adds the signals and divides by the case volume. The built-in clock/timer function of the PLC starts when the first eggs are dropped, and continues to run throughout the day. “No matter what happens, unless you manually stop the clock, it’s doing the calculations on how many actual cases per hour you’re running,” he adds. Jesse chose to use an Optimate OP-414 display panel in conjunction with the DL-06DR PLC to display collected data. The display also shows the daily running total and the number of cases per station.
Jesse also uses the DL-06DR PLC with an H0-ECOM Ethernet module for monitoring water consumption. Each barn’s control system is networked via Ethernet, where the PLC reads pulses from water meters on individual water lines. Using DataWorx Ethernet data logging software, the information is captured for display in Microsoft Excel worksheets. With this information, Jesse can chart and compare water consumption, which is very important in monitoring the health of the hens.
With the new system in place, the egg gathering no longer needs to be monitored by a human. Initial estimates show labor savings of $70,000–$80,000 per year. This increase in efficiency, and continued company growth, has given employees opportunities to take on other positions and responsibilities.
Jesse continues to search for ways to improve the egg processing at Pete and Gerry’s Organics. In the future, he plans to incorporate other methods of PLC control for increasing efficiency, such as water temperature control.
To find out more about Pete and Gerry’s Organics, visit: www.peteandgerrys.com.
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Systems integrator brings automation
into skydiving
by TJ Johns,
Senior Editor
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Thrill seekers around the world are forever looking for the next big adrenaline rush. More of them are finding that thrill through indoor skydiving, which is quickly becoming a way to satisfy the desire for excitement, and yet remove the element of danger.
Indoor skydiving facilities have been in existence globally for several years. However, the controls have been known to be sluggish, undependable, limited in features, and inefficient.
Engineering partners Frank Smith and Bill Alexander of Custom Control Solutions, LLC, in Cumming, GA have developed a newer control system for indoor skydiving tunnels that emphasizes safety and efficiency. The system creates and monitors a smooth air stream which simulates atmospheric properties suitable for skydiving. Frank and Bill have been busy installing systems throughout America, as well as internationally in locations such as Alcantarilla, Spain, Milton Keynes, England, and Moscow.
With its unique architecture, the indoor skydiving structure looks rather unusual. A little over four stories tall, the first floor of the structure consists mainly of open framework, with the exception of a large enclosed bell-like structure at the bottom resembling a space shuttle exhaust. A stairway leads to the second floor which houses the control room, classrooms, and sales center, all surrounding a central circular chamber (the tunnel). Farther up, sitting atop the structure, are four large exhaust fans, designed to pull air up through the central tunnel and exhaust it out the top. This section of the tower houses four 400 hp fans, each controlled by a dedicated Variable Frequency Drive (VFD) located within the structure below. When the fans run simultaneously, internal wind speeds can reach 178 mph.
The indoor skydiving tunnels are open to the general public where customers must first attend class and learn how to tunnel sky dive. Experienced skydivers use the facilities to refine existing skills, and teams around the world use them to create and practice in-air routines with relative safety and without time limitations. According to Alexander, in 30 minutes a skydiving team could practice as many as 15 dives, as opposed to the several hours it would take from an airplane.
The new control system features a PC-based control system with Entivity Studio as both the logic engine and the Human Machine Interface (HMI). The master industrial PC communicates to inputs and outputs (I/O) using an Ethernet connection and collects data from the VFDs using RS-485 Modbus communications. The control system provides the operator with a combination of touch-screen and manual flight controls.
Each VFD is built into a packaged configuration which includes an 18-pulse transformer, input reactor, and high-energy surge protection. The VFDs are controlled via analog and digital signals and the control system receives information over the Modbus link on drive status, faults, power consumption, etc.
For increased safety, most tunnels are equipped with photoelectric sensors, located at specific heights, to help maintain airspeed. If the flier exceeds a predetermined level in the flight chamber, the sensors report to the control system and the fan speed isautomatically adjusted to bring the flier back down to a safe area within the tunnel.
The control system was designed so the operator has a full overview of system status from one main screen. The main screen is divided into functional areas, which help reduce eye fatigue by placing information where the operator doesn’t have to constantly scan the screen. Setup screens are provided for system configuration such as PID tuning, speed limits, door opening and closing times, etc. The operator controls the flight of the skydiver in the tunnel using a joystick co-located with the control computer.
The control system features Ethernet I/O, enclosures, pushbuttons, switches and terminal blocks from AutomationDirect. The DirectLOGIC DL205 hardware platform was chosen for the application based on its wide selection of I/O modules, size, cost and reliability, and ease of integration with Entivity Studio software. A PLC base houses an Ethernet Base Controller (EBC) module in the CPU slot. The program logic is executed in the PC and the I/O rack becomes a transparent extension of the PC itself.
In Milton Keynes, England, the skydiving tunnel uses a different design. The fans are installed horizontally and force recirculated air through outer towers back into the central tunnel. Friction caused by the recirculation heats the air, so each tower is equipped with an adjustable vent door, allowing exhaust of heated air and intake of outside air to control tunnel air temperatures. Alexander states, “For every liter of air I put out through the exhaust door, it pulls in fresh air.” To explain efficiency, he continues, “A four minute flight typically uses less than a dollar of electricity. The efficiency ratio is incredible for the amount of airspeed that’s generated.”
The combination of AutomationDirect I/O, Entivity Software, and VFDs has resulted in a reliable, expandable, and cost-effective control system solution. Since September 2003, the newer control system has logged near-perfect up-time. The wind tunnels operate 24 hours a day, 7 days a week, and host scores of tourists and skydiving teams from around the world.
For more information about the skydiving tunnel or other services from Custom Control Solutions, contact Bill Alexander, 3550 North Parkway Suite 300, Cumming, GA 30040. Phone 770-886-3307, fax 770-886-3882 or email billa@ccsolutionsllc.net.
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Process analyzer uses WinPLC to monitor
cyanide destruction
by ADC Editorial Staff
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NEXTChem Process Analyzers, LLC produces chemical process analyzers for industries such as metal treatment, metal finishing, chemical, wastewater, and pulp and paper. The analyzers automate laboratory measurements used for process control. Some of NEXTChem’s customers include a large aerospace company who uses the analyzer for measuring caustic cleaner for jet engine parts, and a major steel manufacturer who uses it for measuring sulfuric acid in coke oven scrubbers.
Conductivity and pH sensing are the traditional methods for measuring and controlling chemical processes. However, neither of these methods is capable of providing exact chemical concentrations, which severely handicaps the ability to provide useful process control. Laboratory measurements performed with process analyzers are generally one of two types: titration or standard addition. Titration is a measurement technique that uses a chemical reaction to determine a chemical concentration. Standard addition is a measurement technique that uses the response of an ion selective electrode to determine a chemical concentration. Both of these measurements provide precise information on the chemical process and greatly reduce the amount of time it takes, from hours to only minutes, to report chemical measurements.
One customer of NEXTChem is a medical device maker who uses the analyzer to monitor cyanide destruction. Cyanide is used in a metal plating process at the customer’s facility, and the local municipality has a strict limit on the amount of cyanide that can be discharged into sewers. The analyzer is used to confirm that all cyanide is removed from the wastewater before it is discharged into the sewer.
The NEXTChem Basic OMNIChem process analyzer is comprised of AutomationDirect’s DL205 PLC system using a WinPLC CPU and H2-SERIO modules, along with digital and analog I/O modules. The WinPLC is programmed with Entivity Studio software. “The Entivity software makes it possible for non-programmers to create very complex programs, and the DL205 system was small, but powerful enough to be used in our analyzers,” says Tim Pearson of NEXTChem.
The process begins with a D2-TD2-2 digital output module used to activate pilot solenoids, which send air pressure to sample valves, allowing fresh samples into the analyzer. The H2-SERIO module then sends ASCII commands to a stepper motor controller that activates stepper motors in the analyzer. The stepper motors are connected to pumps that control the proper amount of reagent required for the cyanide analysis.
Next, the cyanide ion selective electrode measures the amount of cyanide present in the sample. This concentration is converted into a voltage signal, which is sent to a voltage-to-current converter. The current signal is brought into an F2-08AD-1 analog input module. The WinPLC performs all the necessary calculations to determine the concentration of cyanide present in the sample. Once determined, a signal that represents the concentration of cyanide is transmitted to a SCADA system.
NEXTChem’s customers have enjoyed several benefits from the new system, including lower system costs and faster measurement speed. Tim Pearson of NEXTChem says, “The high quality and low cost of parts from AutomationDirect have enabled NEXTChem to move our process analyzers into the next generation of process control. NEXTChem had considered a proprietary controller using C++ programming; however, the ease of programming offered by the WinPLC enabled bringing the product to market six months earlier than anticipated, and at a lower cost.”
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