Data types of Structured Text (ST)

Just like other programming languages, the IEC 61131-3 programming standard provides many different data types which include both elementary and complex ones. A data type defines how much memory capacity is needed by a variable value and by that, the largest and smallest value in the variable. 1 Elementary data types (INT, REAL, BOOL) The … Read more

HE599ETX200 Using the SmartRail Ethernet I/O with a ModbusTCP client (master)

Overview This application note describes the necessary configurations and settings to establish communications with the HE599ETX200 via ModbusTCP client applications.  This document covers: Boot-P Modbus addressing. ModbusTCP rules specific to the ETX200. Configuration words of individual I/O modules. Setup example using Modbus Poll software. Section 1 Modbus Addressing Input and Output I/O mapping I/O Data … Read more

Application note for English to Cyrillic translation via OCS

Overview This application note describes how to set up an English to Cyrillic translation using the Cscape Font Manager and Language Select functions.  It is a temporary application note in that the font support is likely to undergo improvements in future revisions of Cscape and will therefore look different and set up differently than what … Read more

Pump control with two pumps using Structured Text (ST)

Pump control with two pumps

This example describes a pump control with two pumps and three float switches in a well. The float switches are attached to cables and when the liquid rises in the well, the float switches will be activated and change their NC / NO position. The two submersible pumps M1 and M2 have been set to alternate operation mode, which … Read more

Simulation signals generated using Structured Text (ST)

Sine wave

This chapter describes simulation signals, which can be used during development and testing of the programming code. The machine or the hardware panel is often not available, when the PLC code and program needs to be tested. The hardware has possibly not arrived onsite, the machine is not built yet, or the PLC equipment is … Read more

Simple queue structure with Structured Text (ST)

ARRAY

This example describes the simplest implementation of a queue. A queue is used when e.g. there are many packages on a conveyer belt, waiting for treatment by a machine in a large plant. The packages often require information like weight, receiver, size or content. Weight gives information about a package which must be saved in … Read more

How the PLC executes PLC code ?

The basic mode of operation for a PLC

It is important to know how the PLC executes the program code when writing the program. A PLC executes the program in real-time, which means that the program modules must be executed within a short time-frame. The program modules are executed at a fixed time interval (the PLC scan time) e.g. 50 [ms]. Some of … Read more

PLC Programming Practice-Road roller assembly line

Road roller

Scope of work – Assembly of road roller. An assembly line includes fitting of engine on chassis, fitment of axles, mounting of body, and fitment of wheels and rollers. Conveyor is driven by an electric motor coupled with a gearbox. An electric brake is also connected to the motor that ensures braking of the electric … Read more

PLC programming examples using works2 software

Conveyor application

Conveyor application A box filling line is as shown above. It consists of a flat belt conveyor which carries boxes and a hopper which fills powder into the box. Both conveyor and hopper are controlled by two different VFDs. The quantity of powder can be controlled by rotation of the motor through VFD. A detects … Read more

PLC Programming Practice-Mitsubishi PLC

Analog signals

Mitsubishi PLC series FX PLC SERIES FX-1S PLC FX-1N PLC FX-2N PLC FX-3U PLC FX-3G PLC FX5U PLC Mitsubishi PLC wiring configuration PLC and their programming software PLC Software Q series GT developer FX series GX works2 FX5U GX Works3 Mitsubishi communication protocols USB cable Ethernet Addressing for ladder logic programming Input (X) : Inputs are … Read more