Tag Archives: do-more plc

BRX PLC High Speed IO

The BRX series of programmable logic controllers has built in high speed inputs and outputs. Every CPU will have either 6 or 10 high speed inputs (HSI) available depending on the model. These inputs can be used for input frequencies from 0 to 250Khz. 250Khz represents 250000 input counts per second that can be coming from devices connected to your PLC like an encoder. Every BRX CPU unit also has 2, 4 or 8 high speed outputs (HSO) available depending on the model. The outputs can send a frequency of pulses out up to 250Khz. Due to the speed of the IO, these functions available on the BRX PLC will operate asynchronous with the PLC scan time.
We will be looking at sending an output of pulses at different frequencies from our BRX PLC and inputting these back into the high speed inputs of the PLC. So our output will be wired back into our input. We will then display the frequency of the input pulses and the count. As a system integrator, this ability to send and receive high speed inputs and outputs can prove very useful to you in the field when commissioning your automation system.
Let’s get started with the BRX PLC High Speed IO. Continue Reading!

BRX PLC Counters

A majority of the programmable logic controller (PLC) programs will include a counter instruction. The BRX series of programmable logic controllers have several different counters available for your program. There are five different basic counter instructions in the PLC. The memory area for counters (CT), include the Counter PVs (Present Values) Counter SVs (Set Values) and the Counter Completion Flags. The default size of the counter area is CT0 – CT255. This size can change to the amount that we need for our program. Please see BRX PLC Numbering Systems and Addressing on how to change the memory configuration of the controller.
We will be looking at the counter instructions in the BRX PLC 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. When dealing with counters, we need to look at timing charts. The Secret of Using Counters is a good refresher on using timing charts.
Let’s get started with the BRX PLC Counters. Continue Reading!

BRX PLC Timers

A majority of the programmable logic controller (PLC) programs will include a timer instruction. The BRX series of programmable logic controllers have several different timers available for your program. There are nine different basic timing instructions in the PLC. The memory area for timers, include the Timer PVs (Present Values) Timer SVs (Set Values) and the Timer Completion Flags. The default size of the timer area is T0 – T255. This size can change to the amount that we need for our program. Please see BRX PLC Numbering Systems and Addressing on how to change the memory configuration of the controller.
We will be looking at the timer instructions in the BRX PLC 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. When dealing with timers, we need to look at timing charts. The Secret of Using Timers is a good refresher on using timing charts.
Let’s get started with the BRX PLC Timers. Continue Reading!

BRX PLC First Program

We will now look at writing our first program for the BRX PLC. The Do-More Series allows us to write programs online or offline with the PLC controller. The series will also allow us to do online editing. We can change program information and download the new program between scans of our controller. As a system integrator, this ability can prove very useful to you in the field when troubleshooting your automation system.
Our first program will be the start, stop, jog circuit. Here is a link explaining the logic behind the circuit.
How to Make a Start Stop Jog Circuit in a PLC
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BRX PLC Establishing Communication

We will now use the Do-More Designer software to establish communication with the BRX PLC. This is the same software that we used in the Learn PLC Programming Fee Video Series. Using the Do-More Designer software, we will communicate via USB, RS485 and Ethernet. These three methods will allow us to communicate to our BRX PLC in order to program or troubleshoot this controller. Once we have established communication we will then look at updating the firmware in our controller. Let’s get started. Continue Reading!