Archival of process control data is paramount to tracking of process performance and troubleshooting of issues with the process plant. Modbus is used heavily to acquire process data via the use of Human Machine Interfaces (HMIs). HMI's typically have the ability to not only read real-time data but also to archive that data for further analysis. A frequent drawback of HMIs is that archived data is usually stored in a proprietary format, which can make porting data to other system for further analysis problematic.
This course details the use of the Winlog Lite HMI in archiving process data directly to a Microsoft Access database as well as a Microsoft Excel workbook. By being able to do this type of archival, porting of data becomes much easier and faster.
The course uses a Modbus slave simulator from which the HMI acquires a single data point which is deemed a line pressure. The HMI is then configured to have this data point archived every 10 seconds a Microsoft Access database as well as a Microsoft Excel file. Structured Query Language (SQL) is introduced to the student as well as an example of HMI scripting.
The course is very practical and the student can perform all tasks that are shown in the videos. In fact, throughout the course, students are strongly encouraged to do all that is show in the videos for maximum learning effect.
Modsim32 is a Modbus slave simulation application. It will be used to provide data values that will be read by the HMI application and logged to Access and Excel.
Virtual Serial Port kit is an application that creates virtual com ports in Windows. It creates the ports in pairs and ties them together in a null modem fashion.
Winlog Lite is an HMI Development Application. It will be used to build an HMI application that will read data from the Modbus slave and then constantly log those data values to Access and Excel.
Modsim32 is configured as a Modbus slave device with only 1 Input Register. A single virtual port pair is configured in Virtual Serial Port kit.
Channels, Devices and Gates are configured in the application to acquire data from a single input register in Modsim32.
A template screen is configured with a single object to view the value. The HMI application is then run.
The MS Access database as well as the Excel file will act as data stores for the logged data.
Data Source Names allow databases of different types to be interfaced to in a common way.
This command is used to insert new data into a database table.
This command is used to read data from a database table.
A new channel (#2) is configured to link to the ODBC DSN, which is connected to the MS Access database.
A gate is created, whose value will be written to the VALUESP column of the database table.
A code script called "Main'" is written with periodically copies the value of LINE_PRESSURE to LINE_PRESSURE_DB.
The HMI application is run and the Modbus value is changed in Modsim32. The database is then opened to check for logged data.
The HMI application is modified and then run again to see if data is being logged to the excel file.
What to do next to keep further solidify learning.
I have been working in the fields of Software Development, Software Systems Integration and Process Automation since 1996. In 2003, I stepped out on my own and started working for myself providing software development and systems integration services to small and medium businesses.
I am also associated with a great company called Mora Systems Limited that under the leadership of it's Managing Director has produced innovative and outstanding products and services in the fields of GIS and Cellular based SCADA.
Teaching has always been a passion for me. I have taught at the tertiary level for many years on the subjects of programming, control systems as well as systems integration. In the last few years I found myself incorporating more and more videos into the curriculum with amazing results.
When I heard of uDemy I just could not help but sign up. With teaching in a classroom, you can reach only so many students, but with uDemy you can reach the world! I plan to publish and promote as many courses as I possibly can on the uDemy platform.