Category Archives: Communication

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!

PLC Programming Example – Pick and Place

We will apply the five steps to PLC program development to a pick and place robot example. The example will use a BRX PLC communicating to Factory IO (3D Software Simulator). 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.
Five Steps to PLC Program Development – Press
PLC Programming Examples:
Process Mixer
Shift Register (Conveyor Reject)
Paint Spraying
Delay Starting of 7 Motors

Define the task: (1)
Watch the sequence of operation video below.
Watch on YouTube : PLC Programming Example – Pick and Place Testing
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!

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!

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!

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!

Creating 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 Management Studio (SSMS) to create a database. The SQL Server database will be created so we can connect to it for data acquisition (data logging) from our PLC applications. Continue Reading!

Omron CP1H Setting, Forcing and Online Editing

The Omron CP1H series of programmable logic controllers is capable of online programming. This is when the PLC is solving logic and at the end of the scan, programming logic is added or modified. The next scan will now solve the new or modified logic in the PLC. CX-Programmer can also set or force inputs and outputs in the controller. This is usually used for troubleshooting and testing of the PLC logic. We will use the Start Stop and Jog circuit that we have developed to test the program in the PLC. Forcing and setting the inputs and outputs will demonstrate to us the operation of the logic. Online programming (online editing) will also be done with our CP1H controller. Continue Reading!

Omron CP1H Establish Communication

The Omron CP1H series of programmable logic controllers is programmed from CX-Programmer. CX-Programmer is part of Omron CX-One Factory Automation Integrated Tool Package. We will now establish communication to our CP1H PLC using CX Programmer. We will be using the USB connection (Built into the CPU) as well as a RS485 connection using the CP1W-CIF11 module. The Start Stop and Jog circuit that we developed last time will be transferred to the PLC unit. We will then verify that the program in the PLC is the same as the program logic in CX Programmer. Continue Reading!