Tag Archives: host engineering plc

BRX PLC Program Control

The program control instructions will allow us to specify what parts of the logic get solved and when this happens. This will control how the PLC will scan and solve your logic in your program using a synchronous PLC Scan. Understanding the PLC program scan will explain the synchronous and asynchronous program scanning. Ladder logic programs get solved left to right, top to bottom. The result of the rung before is available for the next rung.
Using programs, tasks and subroutines in our BRX Series PLC we can divide up our program into smaller segments. This will help when we troubleshoot the system in the field as the system integrator. Let’s look at some samples of each of the above mentioned methods. Continue Reading!

Modbus RTU BRX PLC Master to Click PLC Slave Communication

Recently I was asked to demonstrate communication between a BRX PLC and Click PLC using Modbus RTU. Both PLCs are available from automation direct com. Modbus serial communication (Modbus RTU) is a standard protocol used in many automation devices. It works on a Master / Slave configuration. You can have only one master per network on Modbus RTU (Remote Terminal Unit). A maximum of 32 devices (Nodes) on the network can communicate to the master. A review of the Modbus RTU protocol (RTU frames) can be seen at the following URL.
http://www.rtaautomation.com/technologies/modbus-rtu/
Using the BRX PLC as a Master, we will be communicating to the Click PLC (Slave). Our example will read 10 registers from the Click PLC and write 10 registers from the BRX PLC. Let’s get started! Continue Reading!

BRX PLC Online Editing and Debug Mode

Our first program for the BRX PLC involved a start stop jog circuit. We will now use the Do-More Designer Software to modify this program while the PLC is scanning the logic. This is referred to as online programming or online editing. As a system integrator, this ability can prove very useful to you in the field when commissioning your automation system.
We will also be using the special Debug Mode of the software to monitor the ladder logic status and bits on a scan by scan basis. Forcing the inputs and outputs, we will control the execution of the PLC scan. This is a great feature of the Do-More Designer software.
Here is a link explaining the logic behind our circuit.
How to Make a Start Stop Jog Circuit in a PLC
Let’s get started. Continue Reading!

BRX PLC Installing the Software

The BRX PLC uses the Do-More Designer software which can be downloaded free of charge and includes a simulator. The latest Do-More Designer software version is 2.0.3. This is the same software that we used in the Learn PLC Programming Fee Video Series.
The Do-More Designer software can be used to program the whole series of programmable logic controllers.

Do-More H2 (Micro Modular PLC)
Do-More T1H (Stackable PLC)
BRX Series PLC (Stackable Micro Brick)
We will be installing and reviewing the Do-More Designer software version 2.0.3. Version 2 is mainly to accommodate the new BRX Series PLC. Continue Reading!

BRX PLC System Hardware

The BRX series of programmable logic controllers is a stackable micro brick. This is sometimes also referred to as a shoebox PLC because of the shape and way in which expansion modules are added. This new BRX series PLC is the latest in the Do-More series of controllers that have hit the market.

Do-More H2 (Micro Modular PLC)
Do-More T1H (Stackable PLC)
BRX Series PLC (Stackable Micro Brick)

The BRX series offer built-in data logging, integrated motion control, customization communication ports and expansion capabilities. These features like other Automation Direct products are offered at a very good price point. BRX series of controllers will use the same software as the other Do-More PLCs (Do-More Designer) and is a free download. We will be looking at this full featured software that comes with a simulator later in this series.

We will be walking through allot of the features of this powerful controller. Let’s start by looking at the hardware. Continue Reading!