Makers Blog

Following on my previous blog "Datalogging in IEC 61131-3: The basic principle", I want to show you something extra.
To read and write data, you only need to implement some basic commands.

In this blog, we are going to create the following methods:

• Create a file
• Create a file and directly write a header line
• Delete a file
• Read a line
• Write a line

Please note that some extra error handling is needed for real life applications.

If you are interested in the complete PLCnext Engineer project, just let me know. (This email address is being protected from spambots. You need JavaScript enabled to view it.)

About 90 percent of operating problems faced by engineers can be solved by remote access to the control system. With remote access, you can remotely troubleshoot and program your PLCnext controller. 

A prerequisite for remote access is that machines can be accessed from the internet in a secure way. After all, nobody wants to undermine the security or daily operations of the parties involved.

Introduction:

On the PLC, the file /etc/plcnext/Device.acf.settings contains a list of environment variables and their default values. Some of these environment variables are used to enable/disable various system services on the PLC.

It is possible to change the values of these environment variables, but this should not be done by editing this (or any other) system configuration file.

Here is a basic guide to installing PLCnext CLI version 2020.0 LTS on a Linux operating system, when there is an earlier version of the CLI already installed.

The procedure below assumes that there is an existing PLCnext CLI installation on the Linux host, in the directory ~/plcncli.

1. Download the file "SDK und PLCnCLI für Linux 64-Bit" from the Downloads page for the AXC F 2152.

PLCnext Technology offers different possibilities to capture data.

Some examples:

• PLCnext Engineer library: The function blocks for Data Logging are used to collect data of any data types and store into csv or binary files. In combination with the PLCnextBaseLibrary it is possible to copy the data to an FTP server.
• Datalogger: A service component of the PLCnext Technology firmware. This component transfers real-time data from the GDS to a database for recording and storage purposes. When starting and stopping the PLCnext Technology firmware, the DataLogger is started and stopped automatically. XML configuration files are used for configuration of the DataLogger. The DataLogger can record data from any IN or OUT ports and variables.
• App available in the PLCnext Store: DataLogger powered by FourZero

If you want to build something specific for your application, this blog is what you need.

For those who are unfamiliar with the details of the PLCnext architecture, the following diagram might proof helpful.

As you can see non real-time components can communicate with the PLCnext runtime via Remote Service Calls and Access to shared data with the GDS and the the Operating System APIs. There are services running on the PLC exposing a part of this functionality to the network and these are the service we are going to use to create a simple GUI-Application that will use some of the available services.

Depending on the  project at hand, sometimes there is a need to rely on Time table and schedule functionality. Especially in building applications, but can be practical in lots of situations.

Because this is really well integrated in the Emalytics (Niagara) framework (which we have on the ILC2050 BI controller), I decided to make a makersblog where I explaine the functionality of this and integrate the output of this schedule/calendar function into the AXC F 2152  via Modbus TCP.