Industrial Automation, PLC, VFD, and Troubleshooting
In PLC systems, not all signals are the same.
Some signals are simple ON/OFF signals. Other signals represent a changing value such as pressure, temperature, tank level, speed, or weight.
That is …
Read MoreOne of the most confusing topics for many automation technicians is sinking and sourcing.
You may hear people say:
PNP sensorNPN sensorSourcing inputSinking inputCurrent sourcingCurrent sinking
At first, it sounds complicated. But the …
Read MorePLC Addressing: Rack/Slot vs Tag-Based
In a PLC system, every input, output, and internal memory location needs a way to be identified by the controller.
This identification method is called addressing.
In simple …
Read MoreBefore learning advanced PLC programming, every automation technician must understand the basic logic operations used in ladder logic.
The three most important logic functions are:
AND
OR
NOT
These are the foundation of almost every …
Read MoreLadder Logic is one of the most common PLC programming languages used in industrial automation.
It was designed to look similar to electrical relay control circuits, which makes it easier for …
Read MoreSeal-In Circuits Explained
A seal-in circuit is one of the most important basic patterns in PLC ladder logic and relay logic.
It is commonly used when an operator presses a momentary Start …
Read MoreAn interlock is a condition used to prevent two incompatible or unsafe actions from happening at the same time.
In simple words:
An interlock blocks an action when another condition makes that …
Read MoreTimers are one of the most common instructions used in PLC programming.
A timer allows the PLC to use time as part of the control logic.
In simple words:
A PLC timer waits …
Read MoreIn the previous post, we covered the basic PLC timer instructions:
TON = Timer On Delay
TOF = Timer Off Delay
RTO = Retentive Timer On
Now we are going one step deeper.
In real …
Read More