We will now configure and operate Analog inputs and outputs on our BRX Do-More controller. One of the features of the BRX Series PLC is the ability to expand its capability to fit your application. This is easily done by “snap-on” modules that will fit on the side of the BRX MPU (Multi-Processor Unit). As we have seen before in the BRX PLC System Configuration post we can add additional discrete inputs and outputs. Automation Direct now offers Analog Voltage and Analog Current input and output modules. These modules come as an 8 point channel unit. There is also a 4 point thermocouple input module also available. We will be configuring, scaling and programming the Analog input and output Voltage modules for our BRX PLC. Let’s get started. Continue Reading!
Modbus TCP will be used to connect AdvancedHMI to our BRX Do-More controller using Ethernet. 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 BRX Do-More Series PLC.
Our sample BRX Do-More PLC program will display a digital panel meter and a gauge of a value in the PLC. Stop and start momentary pushbuttons on the HMI will allow this number to increase or stop. An indication will turn green when the number is increasing and red when it has stopped. The AdvancedHMI package will communicate Modbus TCP over Ethernet to the BRX Do-More PLC. We will be able to monitor our process via the AdvancedHMI window. Let’s get started. Watch on YouTube…
We will apply the five steps to PLC program development to a palletizer example. Our example will allow you to determine how many layers of boxes you want on each skid.
Developing the PLC program is a process that can be clearly defined. In our series on the five steps to PLC program development, we have done some similar practical examples.
PLC Programming Examples – Five Steps to PLC Program Development
– Process Mixer
– Shift Register (Conveyor Reject)
– Paint Spraying
– Delay Starting of 7 Motors
– Pick and Place
– Sorting Station (Shift Register)
Define the task: (1) – Palletizer PLC Programming Example
Watch the sequence of operation video below. This will demonstrate the pallet layer selection, running, and resetting of the machine. (Palletizer)
Watch on YouTube: PLC Programming Example – Palletizer Testing
Compare instruction is often used in PLC programs to test pairs of values. The output of this comparison conditions the logical continuity of a rung. The BRX Do-More series of programmable logic controllers have the following compare contact instructions.
= (if Equal contact)
<> (if Not Equal contact)
> (if Greater Than contact)
>= (if Greater Than or Equal contact)
< (if Less Than contact)
<= (if Less Than or Equal contact)
Besides this instruction, the BRX Do-More PLC will also have to compare instructions for the built-in real-time clock of the system. We will be looking at these instructions along with some programming examples. As a system integrator, this ability can prove very useful to you in the field when commissioning your automation system.
Let’s get started with the BRX Do-More PLC Compare Instructions. Continue Reading!
We will look at numbering systems in our BRX Do-More controller. This will include physical IO, casting, and indirect addressing. The BRX Do-More PLC like all of the PLCs in the Do-More Series use strong data typing. This means that there are fixed memory structures to work within your program. Errors will be displayed if you try to put the wrong type of value in the memory location. The data structures will automatically assist you in your automation system.
Memory can now be as flexible as you want and need. You can define and allocate all the data memory the way you want it up to specific maximums. As a system integrator, you determine what best fits your automation framework.
We will be looking at the addressing and numbering systems in the BRX Do-More Series PLC. Let’s get started. Continue Reading!