Category Archives: management

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!

Modbus RTU Click PLC Master to BRX PLC Slave Communication

Recently I was asked to demonstrate communication between a Click PLC and BRX 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 Click PLC as a Master we will be communicating to the BRX PLC (Slave). Our example will read 10 registers from the BRX PLC and write 10 registers to the Click PLC. Let’s get started! Keep on Reading!

Sharing a Database in SQL Server Express 2014

Microsoft SQL Server Express 2014 is a free, edition of SQL Server this is ideal for learning and developing desktop, web and small server applications. The database size can be 10 gigabytes in size. SQL Server Express 2014 release includes the full version of SQL Server 2014 Management Studio. We will be using SQL Server 2014 to share the database on a network. The SQL Server database is ideal for applications such as data acquisition (data logging) from our PLC applications. We need to configure the SQL Server database so other computers can access this on the LAN (Local Area Network). Continue Reading!

BRX PLC Numbering Systems and Addressing

The BRX 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 with in 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 Series PLC. Let’s get started. Continue Reading!

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!

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!

Omron CP1H AdvancedHMI Communication

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 Omron CP1H PLC.
Our sample CP1H PLC program will use button and indicators to control a start/stop jog circuit. An analog input into the PLC will be scaled and displayed on a gauge on our AdvancedHMI screen. We will also write information to our 7 segment display on the CPU from our AdvancedHMI screen. This communication will be done using Omron serial host link protocol over a RS485 serial cable. The AdvancedHMI package will run on a windows PC and communicate out the port using a USB to RS485 adapter. Let’s get started. Continue Reading!

Omron CP1H Table Data Instructions

The Omron CP1H programmable logic controller has several different table data processing instructions. These instructions are used to handle table data, stacks and other ranges of data.
We can define a stack of data. With this data we can then do the following: add new data by pushing onto the stack, use FIFO (First In First Out), use LIFO (Last In First Out), find the current stack size and read, overwrite, insert or delete from the stack.
Dimension record tables are used to define the length of each record and the number of records. We can then write and read these records. This is ideal for data acquisition projects.
Other instructions found in the table data processing instructions include searching, summing and finding minimum and maximum values.
We will be looking at these instructions in the Omron CP1H PLC. Examples of the instructions will be presented. Continue Reading!

Omron CP1H Program Control Instructions

The Omron CP1H programmable logic controller has several different ways to control the program and the way in which your program executes. Sequence control, Subroutines, and Step instructions can be used. These are just a few ways in which the controller will execute your logic using a synchronous PLC scan. Understanding the PLC program scan will explain the synchronous and asynchronous program scanning.
Interlocks, Jumps, For Next Loops, Subroutines and Step instructions are some of the ways in which we can control our program in the PLC. We will be looking at some of these instructions in the Omron CP1H PLC. Examples of some of the instructions will be presented. Continue Reading!

Implementing the Omron Host Link Protocol (VB.Net)

Previously we used VB6 (Visual Basic 6) to implement the Omron Host Link Protocol to communicate to our programmable logic controller. (PLC) In part 2 we used Visual Basic for Applications (VBA) to accomplish our host link serial communication. We will now look at using VB.Net to establish and retrieve information in and out of the PLC using host link. (C mode commands)

Hostlink communication protocol is a method developed by Omron for communication to PLC’s and other equipment. This ASCII based protocol is used over RS232 or RS422/RS485. It is a many to one implementation which means that you can communicate with up to 32 devices back to a master. (1:N) This communication on the industrial floor can control PLC’s, Temperature Controllers, Panel Meters, etc.

The Omron CP1H plc will be used with a CP1W-CIF11 (RS485) communication serial link adapter. We will also use a USB-485M Universal Serial Bus to RS485 adapter from automation direct. The video at the end of this post will demonstrate the communications by reading 10 registers form the DM area of the PLC. Continue Reading!