Blog

Entries for 'plc programming'

PLC Cycle Time

Modern PLCs are fast, but with only a few exceptions, they can only do one thing at a time. This is because PLCs are built around single-core processors. In this post, I’ll go over some of the low-level PLC concepts that both make PLCs versatil...


Data Logging with Panasonic GT Series HMIs

If you're interested in storing production, sensor, or other data from your automation system, Panasonic GT series HMIs provide a flexible method for logging data from one or multiple PLCs to any standard SD card. Logs are stored in CSV file...


Generating Buffering Routines on an Allen Bradley PLC Using Excel Macros

Allen Bradley PLC’s, both in RSLogix5000 and Studio5000, use a text-based language to assemble their ladder code. Each rung of contacts and coils can be translated to a line of code. This is a unique feature that gives the user several benefits...


Rockwell FactoryTalk Studio Basics: Global Objects and Tag Substitution

Global Objects in Rockwell Automation / Allen-Bradley's FactoryTalk HMI development environment are useful to bring modularization and efficient repeatability of common elements in your project. This basic feature has been around for a long time,...


Linking PLC UDT Tags to HMI Faceplates and Pop-ups in TIA Portal V13 SP1

PLEASE NOTE: This blog was written using features available in TIA Portal V13 SP1 Update 1. Some of the functionality shown was removed in Update 3, specifically the ability to multiplex UDTs. Hopefully the rest of the information will be still be he...


Source Code Protection For Your SIMATIC S7-1200 PLC in TIA Portal

From time to time, we'll run across situations where a client believes it is necessary to lock down code on a PLC. In some cases, there may be valuable intellectual property they would like to protect. In others, its purpose may be to prevent una...


Source Code Protection in Studio 5000 Logix Designer

While working with a customer on a recent RSLogix 5000 project (now called Studio 5000), there was a need to protect some proprietary source code. In this particular case, DMC had developed a custom Add-On Instruction (AOI) to be used within the proj...


Siemens S7-1200 Serial Communication

Today, I found myself setting up some simple point-to-point serial communication on a Siemens S7-1200. For the current application, I was writing a simple function block to broadcast data to a Red Lion serial slave display, but there are a varie...


Siemens vs Allen-Bradley: Function Blocks

Siemens and Rockwell Automation are two giants competing in industrial automation technology today. Rockwell (aka Allen-Bradley) seems to be more popular in the US market, but Siemens has a larger international customer base. A cursory Google search ...