Practical Tips and Techniques
PLC programs scan cyclically. This means that it is repeated many times and in the same order. The primary sequence of a PLC scan is reading the inputs, executing the program, diagnostics, and communication, and updating the outputs. We will look at these scan items with particular attention to how the ladder logic program is … Read more
Logic circuits in a PLC ladder logic program are either on or off. The inputs change, which will affect the outputs. This can be expressed in a timing diagram. The timing diagram or chart will show you how the ladder logic program will respond to the changing states of the inputs and outputs. This visual … Read more
Normally open (NO) contacts or inputs in the PLC ladder logic program do not mean the same as a wired normally open switch. NO contacts on the ladder logic provide the logic condition for the rung to turn on the output. We will be looking at three things about the normally open (NO) contact on … Read more
The newest Do-More Designer Programming Software (2.9) version 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. We will be communicating to a Solo process temperature controller … Read more
All Solo Standard Process Temperature Controllers that support RS-485 serial communications can use the SL-SOFT configuration and monitoring software. This free package will communicate to monitor multiple SOLO controllers using Modbus RTU or Modbus ASCII protocols. We will be installing the SL-SOFT configuration and monitoring software package on our Windows 10 PC. Communicating through our … Read more
We will now look at the C-More Micro program quick start. This will demonstrate how to quickly get your C-More Micro Program up and communicating to your programmable logic controller. (PLC) The general steps involved with a human-machine interface (HMI) program will include, program development, ladder logic, and HMI program development. We will be breaking … Read more