Productivity PID Loop - Part 3 - Application Example & Hardware Explained

I will next explain the application that we will use as our example and cover the hardware that was put together to make it work. We start with a cylindrical polyethylene tank that can hold up to ten gallons of water or other fluid. We already determined we need the ability to maintain a known volume within the tank that our process will rely on to accurately mix additive as the mixture is being used at a random rate. The volume in the tank will be handled with a small Diaphragm Pump controlled by a variable DC motor controller that can accept a 0 to 10 volt DC analog signal from our Productivity 3000. We will monitor the level in the tank by means of an Ultrasonic Sensor that will produce a 0 to 10 volt DC analog output signal that is proportional to the distance between the sensor and the surface of the water. The sensors output will be connected to a Productivity 3000 Analog Input Module. Here we see a diagram representing the working application. The Process and Reservoir Tanks are shown with the interconnecting tubing for both filling and draining the Process Tank. The Ultrasonic Sensor used to measure water level is shown mounted through the lid of the Process Tank. We will use the level to calculate the volume of water contained in the tank. In our demonstration, a manually operated ball valve will be used to set the rate at which the mixture is used through a siphoning action, with the water returned to a Reservoir Tank, so it can be reused. A hand operated Primer Bulb, as might be used on a gas tank for an outboard engine on a boat, is used to initially start the drainage flow, with a siphon tube used to prevent loss of flow once the system is primed. Much of the design that went into our example application was based on using products that are carried by AutomationDirect. Of course the Productivity 3000 Programmable Automation Controller is our main focus and feature for this tutorial. With its abilities, and the ease of adding a C-more Touch Panel, we are able to quickly setup, control and monitor our application. And it was a no brainer to use ADCs sensors, relays, push buttons, power supplies, protective devices and wiring components to round out the design. Here we see the components from other sources that were used to complete our application design. These included the polyethylene tanks, Diaphragm Pump, DC motor controller, float switch, the Primer Bulb, vinyl tubing, fittings, and a 19 inch relay rack. The arrangement of the equipment used for the example application was designed so all of the components would fit on a portable relay rack. On the front includes the Productivity 3000, C-more Touch Panel, Power On and Emergency Stop push buttons, Process Tank with Ultrasonic Level Sensor and overflow float switch, and a Stack Light Tower mounted off to the side. On the rear are found the ZipLink modules, power supplies, Stride Ethernet switches, relays, circuit protection, DC motor controller, reservoir tank, and Diaphragm Pump with a 12 volt DC motor. Also included are terminal blocks and wire duct to keep the wiring neat. ZipLink modules and cables aided in allowing the wiring to take minimum time. Seen next is a series of wiring diagrams, or if you prefer, schematics, that detail the wiring in our application example. In particular is the use of protective devices and separate DC power supplies for the general DC devices, analog input and output signals, and DC power to the Diaphragm Pump motor. The first diagram includes the Power On, Emergency Stop, relays, float switch and general 24 volt DC circuitry. Sheet 2 of the diagrams shows power and communications to the Productivity 3000 and C-more Touch Panel. Also shown is the 24 volt DC power for the Stride Ethernet switches and the analog signals. Sheet 3 continues with the Productivity 3000 discrete DC input and output I/O modules, and the use of ZipLink modules and cables to make the actual wiring clean and simple to accomplish. The last diagram includes our Productivity 3000 analog input and output modules, ZipLink modules and cables to keep the analog signal wiring simple, connections to the Ultrasonic Sensor, and a Rhino 12 volt DC power supply for the Dart DC motor speed controller used to power the Diaphragm Pump motor. The Ultrasonic Sensors 0 to 10 volts DC signal is wired into the first channel of the analog input module by way of a ZipLink module and interconnecting cable. The first channel of the analog output module, using a ZipLink module and interconnecting cable, provides the 0 to 10 volts DC signal to the Dart DC motor speed controller, which allows the Diaphragm Pump to produce a 0 to 1 gallon per minute flow rate to the Process Tank. Next we need to configure the jumpers on the analog input module so the 0 to 10 VDC signal from the Ultrasonic Sensor can be used to determine the water level in the Process Tank. The P3-04ADS Analog Input Module we have chosen has the ability to be configured to accept either voltage or current signals, and each type of signal can also be configured for different ranges, such as 0 to 5 volts DC, 0 to 10 volts DC, 4 to 20 milliamps, etc. To keep it simple, we will set the Analog Input Module up so all four channels will accept a 0 to 10 volts DC signal. This will provide a 0 to 65,535 count range within our Productivity 3000 ladder logic program. Join me in Part 4 of this video series as I cover configuring our hardware, explain the use of Tagnames, and do some calculations to get our signals into understandable and useful engineering units.