Tag Archives: ladder logic

BRX Do-More PLC Using Modbus IO Scanner Profile


The Do-More Designer Programming Software (2.9) or higher includes a Modbus I/O Scanner with some profiles for Modbus Server (Slave) devices. This will greatly reduce the time it takes to implement and troubleshoot communications in your projects. Modbus communications are done independent of the PLC scan time and will have little or no ladder logic for the program.

Last time we communicated to a Solo process temperature controller via Modbus RTU RS485. (twisted pair) We manually set the Modbus IO scanner, reading the present value (PV) and set value (SV) of the Solo. The writing of the set value (SV) located within the BRX Do-More controller was also done. This was all be done without using any ladder logic code. We will now use the Modbus profile in the Modbus IO Scanner to connect a Click Plus PLC to our RS485 network. Using the Modbus scanner to write and read instructions we will also show how to use the ladder logic code with our scanner. Let’s get started. Continue Reading!

EasyPLC Simulator Robotic Cell Click PLC


The Machine Simulator (MS) is part of the EasyPLC software suite. It has many built-in machines that are used to show different programming techniques. The robotic cell example is one of these machines. This will demonstrate a sequencer example. In this case, an engine is lifted and placed onto a rack. The logic will step through various steps to perform the task.
EasyPLC Simulator Robotic Cell Click PLC
We will be using a Click PLUS PLC and the Click programming software to program this EasyPLC machine simulator engine loader of the robotic cell. This will be done using Modbus TCP (Ethernet) for communications. The program will allow you to start, stop and jog the sequencer. Using the five steps for program development, we will show how this sequencer is programmed. Let’s get started. Keep on Reading!

BRX Do-More Simple Modbus Serial Communication


The newest version of the Do-More Designer Programming Software (2.9) includes a Modbus I/O Scanner. This Modbus scanner will simplify Modbus RTU serial communications to any device. Communications are done independent of the PLC scan time and will have little or no ladder logic for the program.
BRX Do-More Simple Modbus Serial Communication
We will be communicating to a Solo process temperature controller via Modbus RTU RS485. (twisted pair) Setting up the Modbus IO scanner and reading the present value (PV) and set value (SV) of the Solo. We will also write the set value (SV) located within the BRX Do-More controller. Communications will happen without using any ladder logic code. Let’s get started. Continue Reading!

EasyPLC Simulator Productivity PLC Robotic Cell


The Machine Simulator (MS) is part of the EasyPLC software suite. It has many built-in machines that are used to show different programming techniques. The robotic cell example is one of these machines. This will demonstrate a sequencer example. The logic will step through different steps in order to perform the task. In this case, an engine is lifted and placed onto a rack.
EasyPLC Machine Simulator Productivity PLC Robotic Cell
We will be using a Productivity Suite Programming Simulator to program this engine loader of the robotic cell. This will be done using Modbus TCP (Ethernet) for communications. Using the five steps for program development we will show how this sequencer is programmed. Let’s get started. Keep on Reading!

BRX Do-More PLC High-Speed Input Pulse Catch


The High-Speed Input Pulse Catch will set an output that can be seen by the PLC ladder logic scan in response to an input pulse. Inputs that are too fast to reliably be seen by the ladder logic scan time will be seen.
BRX Do-More PLC High-Speed Input Pulse Catch
The BRX Do-More series of programmable logic controllers have built-in high-speed inputs. These inputs can function in Counter, Timer, or Pulse Catch modes. 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. Due to the speed of the inputs, they function on the BRX Do-More PLC asynchronous with the PLC scan time.
We will continue looking at the high-speed inputs on our BRX Do-More PLC, by looking at the pulse catch mode. The pulse catch mode will be set up using the Z phase of our incremental encoder. Pulses will be counted using the input directly in the ladder logic and using the pulse catch bit. Comparisons will be made between the two counts and an output will be turned on when different. Let’s get started. Continue Reading!

Click PLC EasyPLC Warehouse Stacker Example


The Machine Simulator (MS) is part of the EasyPLC software suite. It has many built-in machines that are used to show different programming techniques. The warehouse stacker example is one of these machines. Pallets are loaded and unloaded into the stacker machine. A maximum of 30 pallets can be stored. The stacker will work as a FIFO (First In First Out) device. This means that the pallets are stored in a sequence and retrieved in a sequence.
Click PLC EasyPLC Warehouse Stacker Operation
The Click PLC will be used to program this virtual 3D stacker machine. Indirect addressing (pointers) will be used to track the positions on the stacker to store and retrieve the pallets. Using the Click Plus PLC, we will connect to the warehouse stacking machine. This will be done using Modbus TCP (Ethernet) for communications. Using the five steps for program development we will show how this FIFO is programmed. Let’s get started. Keep on Reading!