Category Archives: Communication

Node-RED Modbus RTU / TCP Communication


Node-RED can easily connect to industrial controls using Modbus communication. Modbus is a master-slave type of communication. Masters will always send the commands to read or write to the slaves on the network. The slaves will respond if the communication is directed at them.
We will be installing the node-red-contrib-modbus palette. This will allow us to communicate Modbus serial (RS485) RTU to a Solo process temperature controller. We will then use Modbus Ethernet TCP to communicate to a Click PLC.
Note: When using Modbus TCP (Ethernet) the master is referred to as the Client and the slave is a Server.
Node-RED Modbus RTU / TCP Communication
Node-RED will be used to create a single Modbus flow. We will communicate to our Solo process temperature controller using Modbus RTU on a serial RS485 network. The present and set values of the controller will be read. These values will then be written to our Click PLC using an Ethernet Modbus TCP network. A set value from an analog input on the Click will be used to then write to the Solo. This will happen every 200 milliseconds or 5 times per second.
Let’s get started using Node-RED for Modbus communication. Continue Reading!

Productivity BRX Do-More EtherNet/IP Remote IO


We will now utilize Ethernet/IP to connect a BRX Do-More PLC as remote IO on a Productivity system. The productivity series of controllers can use explicit and implicit messaging techniques of EtherNet/IP to optimize data exchanges across the network.
Explicit messaging means that the data messages that are transmitted will contain everything needed in order to respond or decode the message. It is a normal client/server relationship with instructions explicitly spelled out in the data messages. This communication happens at times that the Client requests the information.
Implicit messaging means the data messages are streamlined. The device is configured ahead of time to know what to do with the data. This is used for time-critical messages and it functions as a typical scanner/adapter relationship. Implicit messaging is real-time. It has the ability to copy data with minimal additional information because both ends already know exactly what each bit and byte.
Productivity 1000 Series PLC BRX Do-More EthernetIP Remote IO
A BRX Do-More PLC will be set up as remote distributed inputs and outputs for our Productivity 1000 controller. Implicit Ethernet IP will be set up. The Do-More will be the Ethernet IP adapter and the Productivity will be the Ethernet IP scanner. Let’s get started. Keep on Reading!

Productivity 1000 PLC Click EtherNetIP Remote IO


We will now utilize Ethernet/IP to connect a Click PLC as remote IO on a Productivity system. The productivity series of controllers can use explicit and implicit messaging techniques of EtherNet/IP to optimize data exchanges across the network.
Explicit messaging means that the data messages that are transmitted will contain everything needed in order to respond or decode the message. It is a normal client/server relationship with instructions explicitly spelled out in the data messages. This communication happens at times that the Client requests the information.
Implicit messaging means the data messages are streamlined. The device is configured ahead of time to know what to do with the data. This is used for time-critical messages and it functions as a typical scanner/adapter relationship. Implicit messaging is real-time. It has the ability to copy data with minimal additional information because both ends already know exactly what each bit and byte.
Productivity 1000 Series PLC Click EthernetIP Remote IO
A Click PLC will be set up as remote distributed inputs and outputs for our Productivity 1000 controller. Implicit Ethernet IP will be set up. The Click will be the Ethernet IP adapter and the Productivity will be the Ethernet IP scanner. Let’s get started. Keep on Reading!

BRX Do-More PLC FTP Client Get Put


We will look at the BRX Do-More FTP (File Transfer Protocol) on our PLC. Using FTPGET and FTPPUT instructions we can transfer files to an FTP server. Our BRX Do-More PLC now has the ability to be an FTP Client. This will allow us to transfer our logged files to an FTP server that we programmed in the following post.
Data LoggingVideo
As an FTP Client, the Do-More PLC now has the ability to transfer and retrieve files from the network at an appropriate time in the PLC logic.
BRX Do-More PLC FTP Client Get Put Windows 10 FTP Server
We will be setting up a Windows 10 FTP server on our computer. Using the FTPPUT FTP Client command on our BRX Do-More PLC we will store a file on our FTP server. The FTPGET Client command instruction will be used to retrieve a recipe text file on our server. This recipe file will have three timers that we will be used in a sample program to turn on some outputs. Let’s get started. Continue Reading!

Productivity Open P1AM Arduino Modbus TCP Client to Click PLC


We will now connect our Productivity Open P1AM Arduino to a Click PLC. Using Modbus TCP the Arduino will be the Client (Master) and the Click will be the Server (Slave).
Productivity Open P1AM Arduino Modbus TCP Client to Click PLC
We will explain how to connect our P1AM-ETH Industrial Arduino Ethernet Shield to the Click PLC. The protocol will be Modbus TCP on an Ethernet communication network. Modbus is a master-slave type of communication. Masters will always send the commands to read or write to the slaves on the network. The slaves will respond if the communication is directed at them. Since this is an Ethernet network our master is known as a client and the slave as a server.
The P1AM Example from Automation Direct on GitHub will be used. It will be modified to write to holding registers and coils in the Click PLC.
github.com/AutomationDirect/P1AM-Examples/tree/master/P1AM-100_ModbusTCP_Client_Multiple
The temperature from the thermocouple input unit on the P1AM will be written to the Click PLC. Inputs from the simulator input card on our Arduino P1AM will be written to the Click PLC outputs directly. The Click PLC will also be programmed with a heartbeat circuit. This will detect if communications have been severed and will reset the outputs after 5 seconds. Let’s get started with our Arduino P1AM Modbus client to Click Modbus server. Continue Reading!