A proximity sensor (switch) is able to detect object presence without physical contact like a limit switch. No physical contact means that the switch has no parts that will wear out. The life span of the sensor is increased with less maintenance.
A capacitive proximity sensor will detect ferrous and non-ferrous objects. The sensor works by oscillating the charge on the plates in the sensor. When an object is placed in front of the surface, the amount of current flow is detected. (Capacitance) The dielectric of objects will determine the distance that the object can be detected.
We will be wiring a capacitive proximity switch into the input of our Click PLC. The CK1-00-2H is an 18mm diameter, NPN/PNP N.O./N.C. selectable output with a 12mm sensing distance. That means that the sensor can be wired as positive (Sourcing) or negative (Sinking) switch. This unshielded 10 Hz switching frequency sensor also has a 4-pin M12 quick disconnect. Let’s get started. Continue Reading!
A push button (pushbutton) is a simple human interface for controlling some aspect of a machine or process. The push button requires a force to push the button to change the electrical operation from off to on or vice versa. The condition of the output is usually momentarily. Some common everyday pushbuttons we use are keyboards keys.
A selector switch is also a mechanical device that will require a force to turn the electrical operation from off to on or vice versa. The selector switch usually locks into a position.
We will be wiring two illuminated pushbutton switches into our Click PLC. A selector switch will also be wired in. Let’s get started. Continue Reading!
The Productivity 1000 series of programmable logic controllers has a slim stackable super compact design. This is sometimes also referred to as a shoebox PLC because of the shape and way in which expansion modules are added. This new Productivity 1000 series PLC is the latest in the Productivity series of controllers that have hit the market.
Productivity 1000 (Stackable Micro PLC)
Productivity 2000 (Micro Modular Programmable Controller)
Productivity 3000 (Modular Programmable Controller)
These three series currently make up the Productivity Series form Automation Direct.
The Productivity 1000 series PLC provides the following features for your automation control panel.
– 50MB user memory – Can handle very complex applications easily.
– 4 built-in communication ports – Easy connectivity to your network. This would include your PC, HMI, Networks, etc.
– Data logging up to 32 GB on a microSD card
– Add up to 8 IP modules to communicate to your field sensors. This will give you a total of 128 discrete IO points or 32 analog IO channels.
– Free Software and 30 days of free training with every CPU from Automation Direct.
– Interactive PLC Configuration Tool
– Tag Names
– Auto discovery IO – Physical I/O tags will be generated based on each module’s position in the base. You can also reconfigure the setup and assign new tags manually.
– I/O Modules have QR codes under the wiring cover. This can be scanned so you can have the latest specifications / wiring diagrams for the module.
– Limitless PID – Auto tuning – Individual or Cascade Mode – etc
– Web Server and Mobile Access
– Advanced Software instruction set
We will be looking at allot of these features of this powerful controller. Let’s start by looking at the hardware. Continue Reading!
Advanced HMI is a powerful, adaptable HMI/SCADA (Supervisory Control and Data Acquisition) development package that takes advantage of Visual Studio. There is no coding required and you can simply drag and drop items onto the page. The best thing is that the software is free. We will look at using AdvancedHMI with the Omron CP1H PLC.
Our sample CP1H PLC program will use button and indicators to control a start/stop jog circuit. An analog input into the PLC will be scaled and displayed on a gauge on our AdvancedHMI screen. We will also write information to our 7 segment display on the CPU from our AdvancedHMI screen. This communication will be done using Omron serial host link protocol over a RS485 serial cable. The AdvancedHMI package will run on a windows PC and communicate out the port using a USB to RS485 adapter. Let’s get started. Continue Reading!
The data control instructions in the Omron CP1H programmable logic controller are used to manipulate the outputs based upon control conditions. Control is the main purpose of these instructions within the PLC. Instructions include PID (Proportional, Integral and Derivative), PID with Auto tuning, Dead Band Control, Limit, Dead Zone Control, Time Proportional Output, Scaling, etc.
We will be looking at some of these instructions in the Omron CP1H PLC. Examples of the instructions will be presented. Continue Reading!
The Omron CP1H programmable logic controller has several different table data processing instructions. These instructions are used to handle table data, stacks and other ranges of data.
We can define a stack of data. With this data we can then do the following: add new data by pushing onto the stack, use FIFO (First In First Out), use LIFO (Last In First Out), find the current stack size and read, overwrite, insert or delete from the stack.
Dimension record tables are used to define the length of each record and the number of records. We can then write and read these records. This is ideal for data acquisition projects.
Other instructions found in the table data processing instructions include searching, summing and finding minimum and maximum values.
We will be looking at these instructions in the Omron CP1H PLC. Examples of the instructions will be presented. Continue Reading!
Programmable logic controller programming is all about manipulating the bits within the memory of the controller. Sometimes we need to convert from one form to another. This is where we will use data conversion instructions. BCD to Binary, Line to Column, Grey Scale and Multiplexing are just some of the data conversion instructions. We will be looking at some of these instructions in the Omron CP1H PLC. Examples of some of the instructions will be presented. Continue Reading!
PLC programming is all about how we can manipulate the information stored in the PLC. We have already looked at timers, counters, moves and comparison instructions. Data shifting is a different concept that will move bits and words around in memory. This is necessary usually for tracking purposes. The word or bit will represent product or information. As this information is triggered to shift to a new location we can use this to activate items latter in the process. A typical example of this would be parts on a conveyor belt. As the part is detected on one end it will turn on a bit in a register. The conveyor movement is usually picked put by an encoder and shifts this bit in the register in sync with the conveyor movement. At the other end of the conveyor belt we can see the bit position and do something with this information. We can use this information to count, reject etc. Looking at the entire register full of bits, we can determine everything on the conveyor and its position.
We will be looking at the data shifting instructions in the Omron CP1H PLC. Examples of some of the instructions will be presented. The instructions are used to shift data within or between words, but in different amounts and directions. Continue Reading!
We will create a simple and inexpensive analog voltage tester for a PLC using a potentiometer and a 9VDC battery. The potentiometer will be 5K ohms. This should be enough impedance for most analog inputs of the programmable logic controller. (PLC) Voltage impedance for analog voltage inputs are in the mega ohm range where current input is typically 250 ohms. Our tester will be for analog voltage inputs (0-10 VDC). Check your input specifications before wiring anything to your PLC. I have used this tester for other voltage inputs along with a meter to ensure that the voltage levels do not get out of range for the input signal.
Analog inputs to the PLC are continuous and can come in a variety of signals. These signals can come from temperature, flow rate, pressure, distance, etc. Continue Reading!
Just about every program usually has some data comparison instruction. This is the ability to compare information from one area of the controller to another and act on results. The Omron CP1H series of programmable logic controllers provide several different ways to compare information. We will be looking at several different ways in which we can do this with some programming examples. Sometimes the instruction used for data comparison in the Omron CP1H will determine the kind of data that we are comparing. You must look at the individual instructions to determine if this is the case or not. Continue Reading!