PLC Electric Motor Interlocks
Programmable Logic Controller Questions and Answers The following PLC program was written to control the operation of a large electric
PLC Tutorials
Tutorials of Programmable Logic Controller – Learn PLC programs and ladder logic lectures of GE, ABB, Siemens, Allen Bradley, Omron PLC’s.
PLC Data Comparison Instructions
As we have seen with counter and timers, some PLC instructions generate digital values other than simple Boolean (on/off) signals.
PLC Math instructions
The IEC 61131-3 standard specifies several dedicated ladder instructions for performing arithmetic calculations. Some of them are shown here: PLC
PLC Timer Instructions
A timer is a PLC instruction measuring the amount of time elapsed following an event. Timer instructions come in two
PLC Counter Instructions
A counter is a PLC instruction that either increments (counts up) or decrements (counts down) an integer number value when
PLC Memory Mapping and I/O addressing
A wise PLC programmer once told me that the first thing any aspiring programmer should learn about the PLC they
What is Human Machine Interface (HMI) ?
Programmable logic controllers are built to input various signal types (discrete, analog), execute control algorithms on those signals, and then
Animation of Electromagnetic Relay
When a voltage is applied to the coil, a current passes through it and this creates a magnetic circuit which
PLC Analog I/O and Network I/O
In the early days of programmable logic controllers, processor speed and memory were too limited to support anything but discrete
PLC Alarm and Trip Documentation
A vast amount of documentation is required for the design and construction of a process facility, which are front-end and