Category Archives: PLC

Click PLC PID using Factory IO

A PID (Proportional, Integral, and Derivative) control is possible with the Click PLC. A sample program was written for this PLC by Bernie Carlton in the following thread from the Automation Direct Forum. This was based on the math/process presented by Tim Wescott on is paper titled PID without a Ph.D. We will be using this sample program along with a Factory IO scene to demonstrate PID control using our Click PLC.

Here are some references on PID control:
PID without a Ph.D. By Tim Wescott
Understanding PID in 4 minutes
PID Control – A brief introduction
PID Controllers Explained
Who Else Wants to Learn about On-Off and PID Control?
Our Factory IO scene will be controlling the level of water in a tank. PID will be used to maintain the level based on a dial pot knob on the control panel. We will also discuss the math that the PID loop uses. Let’s get started! Keep on Reading!

BRX PLC INC DEC 512 Registers for DMX512

I was recently asked the following question after posting the Analog Dust to Dawn program:
” I was wondering if there’s an easy way to increment and decrement a range of values.
e.g. I have a range of registers (V100 ~V611) the values in each register are different. But I want to increment or decrement all the registers values by 1 at the same time. So that the ramp rate is the same.
Is that possible without having to do 6 rungs of logic for each register?
To elaborate a little on my use case. 512 registers were chosen because that equals one DMX universe. So my scaling factor is 0~255.
16 channels are mapped to two BX-08DA-2B modules to control 0-10 fixtures. All other channels are mapped to SERIO module to control DMX512 fixtures and other devices.”

We will be looking at the DMX512 protocol and how to control 512 registers at a time using our BRX PLC (Do-More). Let’s get started! Continue Reading!

Universal Signal Conditioner and Isolator

Signal conditioners are used with analog current and voltage signals. They have the ability to change your input analog signal to another output analog signal. As an example, we can have 4-20mA analog input and change it to a 0-10VDC output signal so we can wire this into our PLC. Typically signal conditioners will also electrically isolate the input and output signals. This is either done by magnetic or optical isolation. You would usually specify the input and output signals that are required in your circuit to choose the signal conditioner required. Using a universal signal conditioner will take a variety of signals and is a great product to use in troubleshooting analog circuits.

We will be using a universal signal conditioner to convert a thermocouple temperature input into a 0-10VDC linear output. This will be wired into the analog card of the Click PLC.
Let’s get started. Continue Reading!

BRX PLC Analog Dusk to Dawn Program

A dusk to dawn sensor usually is discrete on/off of the lighting control. If we want to vary the lights to mimic more of the sunset and rise, we would use an analog output to control the lights. I was recently asked about such a program. Every day they wanted the lights to go off at 10 pm and come back on at 6 am. At 9:30 pm the lights would be on at 70% or 7volts of a 0-10V signal. In the next half hour, the program will bring the lights from 70% down to 0%. In the morning the lights will come back on within the half-hour from 0% to 70%. Poultry Farms are one place that would utilize this program.

We will be developing a program that will do this with our BRX PLC (Do-More). Let’s get started! Continue Reading!

Click PLC Analog Dusk to Dawn Program

A dusk to dawn sensor usually is discrete on/off of the lighting control. If we want to vary the lights to mimic more of the sunset and rise, we would use an analog output to control the lights. I was recently asked about such a program. Every day they wanted the lights to go off at 10 pm and come back on at 6 am. At 9:30 pm the lights would be on at 70% or 7volts of a 0-10V signal. In the next half hour, the program will bring the lights from 70% down to 0%. In the morning the lights will come back on within the half-hour from 0% to 70%. Poultry Farms are one place that would utilize this program.

We will be developing a program that will do this with our Click PLC. Let’s get started! Keep on Reading!

Wiring an Ultrasonic Proximity Sensor to the Click PLC

An ultrasonic sensor (switch) is able to detect object presence without physical contact (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.
An ultrasonic sensor will use sound waves to detect objects. These sound waves are at a level that we cannot hear. Distance is measured by the time it takes to send and receive the ultrasonic wave. Objects can be measured the same no matter what the colour, transparency, shininess, or lighting conditions of the application.

We will be wiring an ultrasonic sensor into the input of our Click PLC. This will include a discrete and analog input signal. The UK1F-E7-0A is an 18mm diameter sensor that has a PNP N.O./N.C. selectable output with analog output of 0 -10 VDC. The sensing distance is 200mm to 2200mm and has a one-hertz switching capacity. A 4-pin M12 quick disconnect is available but we will be wiring in our 2m wired version. Let’s get started. Continue Reading!

BRX PLC HTTP JSON Instructions

One of the features of the BRX Series PLC is the ability to expand its capability to fit your application. Software and hardware changes are ongoing so the PLC can grow with your needs. Communication is something that the BRX PLC can do very well. As part of the internet of things (IoT), the BRX will share and exchange data. You can also refer to this as the industrial internet of things. This will suit several industrial applications.

The Do-more Updates Release 2.5.2 on April 22, 2019, has introduced new instructions. Here are the instructions that we will be using:
HTTPCMD – HTTP Request / Response with Server (BRX only)
JSONPARSE – Parse JSON Text (BRX only)
We will be using these instructions to read the weather conditions from a website. Let’s get started. Continue Reading!

Wiring a Capacitive Proximity NPN PNP Sensor to the Click PLC

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!

Wiring an Inductive Proximity NPN PNP Sensor to the Click PLC

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.
An inductive proximity sensor will detect ferrous metals. The sensor develops an electric field when metal (sensing object) is introduced usually killing the oscillation circuit of the sensor triggering the output.

We will be wiring an inductive proximity switch into the input of our Click PLC. The AM1-A0-4A is an extended range 12mm tubular sensor that can be wired into the PLC as a sink or source input. Let’s get started. Continue Reading!

Wiring Push Buttons and Selector Switch to Click PLC

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!