Tag Archives: plc programming ladder logic

Click PLC Logging Data with Time and Date Stamp




The Click PLC can perform indirect addressing. This means that I can ask for information to be moved to and from locations in the PLC using a pointer that will indicate the address.

Stephen Covey in The 7 Habits of Highly Effective People said: “Begin With the End in Mind.” This is especially true when looking at storing or logging data within the programmable logic controller. (PLC) It is important to fully define what you want to accomplish with your program.

In our Click PLC example, we want to take a series of consecutive memory locations (DS1 to DS10) and store them in memory areas DS100 to DS4100 each minute. We will be able to store 400 entries (400 minutes) in our storage area. Every entry will include the real-time clock (RTC) of the Click. This will show the date and time of each entry. Let’s get started! Keep on Reading!

BRX Do-More PLC MQTT Communications

MQTT stands for Message Queuing Telemetry Transport. This simple publish and subscribe communication protocol does not take too many resources.
Constrained devices with low bandwidth are ideal for MQTT. This protocol provides machine to machine (M2M) connectivity which is ideal for the Internet of Things. (IoT) This protocol is not for remote IO or real-time (deterministic) applications. MQTT is a good solution for applications that move data from hundreds or thousands of machines (sensors) to clients in many networks.

We will be installing a windows based broker called Mosquitto. The Do-More BRX PLC will be one of the clients publishing and subscribing to the MQTT broker. MQTT Lens (Chrome Browser App) will be the other client publishing and subscribing to the MQTT broker. Each client will share information. Let’s get started. Continue Reading!

BRX Do-More Simulator MQTT Publish Subscribe

MQTT stands for Message Queuing Telemetry Transport. It is a simple publish and subscribe communication protocol that does not take too many resources.
Constrained devices with low bandwidth are ideal for MQTT. This protocol provides machine to machine (M2M) connectivity which is ideal for the Internet of Things (IoT) or Industrial Internet of Things. (IIoT)

We will be using a free on-line public MQTT broker from HiveMQ. Messages will be published and subscribed to by two clients. The first will be an MQTT Browser Client by HiveMQ. The Do-More Designer Simulator PLC will be the second MQTT Client. Information in the form of bits and words will be published and sent to both clients. Let’s get started. Continue Reading!

BRX PLC PID Ramp Soak Profile

The purpose of a ramp soak profile is to make gradual, controlled changes in temperature (Ramp), followed by a temperature hold (Soak) period.
We will be using our Proportional-Integral-Derivative PID Instruction with PWM output that we looked at last time to apply the ramp/soak profile.
Using the immersion heater in a cup of water to keep the temperature at a constant value, we will be adjusting the profile of the temperature as we increase the setpoint (Ramp) and hold that set point for a predetermined time. (Soak) We will then decrease that temperature back to the original setting. (Ramp)

We will be modifying our existing program from our PID with PWM Output post. Let’s get started. Continue Reading!

BRX PLC PID with PWM Output

A Proportional-Integral-Derivative algorithm is a generic Control Loop feedback formula widely used in industrial control systems. A PID algorithm attempts to correct the error between a measured process variable and the desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly and rapidly, to keep the Error to a minimum.

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?
We will be using an immersion heater in a cup of water to keep the temperature at a constant value. Using the Do-More Designer software we will perform an autotune on our PID instruction.
Our immersion heater will be controlled through a relay using time proportional control from our PID output. Let’s get started! Continue Reading!

Click PLC PID Instruction and Autotuning using Factory IO

A PID (Proportional, Integral, and Derivative) control is possible with the Click PLC. The Click Programming Software version 2.50 now includes PID. This features 8 full-featured control loops with an easy graphical user interface (GUI). PID will run on all of the Ethernet-enabled Click PLCs.
We will be using this PID along with a Factory IO scene to demonstrate PID control and Autotuning 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. Let’s get started! Keep on Reading!

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!

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!