Article

Due to the powerful MicroC compiler included in Automa's Super-Flash, Azzali Elettronica was able to develop a program for Benassimpianti that can be configured to manage any type of industrial refrigeration plant. An ingenious IT solution permits to manage up to 145,000 variables.

By Roberto Frazzoli

In plant engineering, companies often have to create completely different plants that may even share the same basic characteristics.
This poses problems when developing the appropriate supervision software, because generally, it is not possible to use the same program to manage different plants, which means developing ad hoc software for each new plant.
This obviously entails high costs and lengthy delivery times, which have negative repercussions on end-users. A solution to this problem is the development of a "universal" supervision software, versatile enough to be applied to all plants by modifying only its configuration.
Azzali Elettronica (Parma) has recently developed this type of program for the company Benassimpianti (Langhirano, PR) using Automa's Super-Flash.
Automa is a software house located in Pedrengo (Bergamo), which is specialized in industrial automation and particularly in process control.
Azzali Elettronica (which was founded in 1987 and employs about fifteen people) has been one of Automa's partners since 1997.
This article describes briefly Azzali Elettronica's application, which is particularly interesting as it uses only Italian technologies to increase competitiveness in Italy's important industry of typical foods.

An application problem: the variety of plants
Benassimpianti is a company specialized in engineering industrial refrigeration and air conditioning systems and machinery for a wide variety of applications. In particular, this company is now a big international name in plant engineering for slaughterhouses, ham and salami factories, dairies and food refrigeration in general.
This company employs about thirty people and uses a lot of information technology. Its air conditioning systems in ham and salami factories are designed not only to conserve meat, but also principally to create the typical seasoning cycle for each particular salami, controlling with utmost precision the temperature and humidity curves depending on the weather conditions.
The problem was that the wide variety of plants built by this company of Langhirano was not able to allow the use of the same supervision software. Benassimpianti, which used normal Scadas available on the market, was therefore forced to carry out costly software development for each installation, which resulted in a waste of time and money.

A technical problem: too many variables
Robert Riccardi from Azzali Elettronica, which was contacted by Benassimpianti, believed that the problem could be solved by using a supervision program designed to anticipate all the possible plant configurations in order to permit a rapid configuration - by using an Ascii initialization file - to be adapted to every specified plant requested by the final customer.
However, this company from Parma explained that a software of this kind would be extremely complex if development was based on normal Scadas available on the market. In fact Azzali Elettronica's analysis revealed that the total number of variables necessary for anticipating all the possible plant configurations used by Benassimpianti would arrive to 120,000. We are talking about address variables to the PLC, also called "tags" by some supervision software suppliers.
An example of a variable is the temperature reading in a seasoning room. A fundamental margin for future expansion would also increase the number of variables to 145,000.
Azzali confirmed that such a high number would be impossible in practice, due to excesive costs (for purchasing the development license and relative supervision system royalties) and response times from the "field", which would be much too slow (as the necessary process for updating all the variables would obviously be extremely long).
Furthermore, it would take far too long to develop this kind of software, which would end up being practically unacceptable for the final customer, considering its costs and perfomance.

The solution: MicroC compiler for variable "indexing"
Azzali Elettronica's Attilio Marusi solved the problem by indexing the variables, which was possible with MicroC compiler included in Automa's Super-Flash.
Super-Flash is a development system that generates Hmi and Scada applications for Windows and Ms-Dos operating systems. The 32-bit system can be easily connected to PLCs, acquisition sheets, numerical controls, terminals, tools, etc.
The software manages serials, networks and highly advanced protocols like Ethernet, NetBios, TCP/IP, H1, Profibus, L2, Sysmac-Link, Dh+, etc. Super-Flash hosts a series of features designed to simplify the developer's work; however the most interesting part here is the MicroC compiler, which allows you to develop procedures with a subset of language C.
This software component - which comes with a powerful library of functions oriented to this problem - allows you to change runtime variable properties, such as the address to the PLC, the PLC node and minimum and maximum limits of permitted values, among other things.
Therefore, it is possible to "index" variables, that is replacing individual quantities for each specific equipment with generic tags that cover all equipments of the same type, by using an index to specify anytime which concrete model it refers to.
For example, without indexing, temperature values for ten identical seasoning rooms correspond to ten separate variables, whereas with indexing it is possible to reduce them to just one variable.
In this way the company was able to dramatically re-evaluate the problem: in fact the number of effective variables dropped from 145,000 to only 3,000. The reduction was particolarly high in recipe management, where input display variables for twenty seasoning stations dropped from 138,000 to 1,380 (a tenth of the original figure).
Thanks to Automa's Super-Flash, the software developed by Giorgio Menozzi from Azzali (called Pcdb, Process Control Device Benassimpianti) was able to communicate with a wide range of pheripherals:

• twenty PLCs connected to each other by field buses and connected to the central system via a serial port or modem
• twenty temperature and humidity gauges connected to each other in multidrop Rs485
• a Gsm modem for sending alarms by Sms or fax
• a serial continuity group for controlled shutdown in the event of power failure
• several remote computers connected via an Ethernet network or modem that allow the application be remotely accessible and therefore display and set production data
• a telesupport computer connected via modem and installed on Benassimpianti's headquarters

Another important characteristic of Pcdb software is its dual system function: complete supervision of the plant or as a simple Hmi display on the seasoning room.
If configured as supervision software, Pcdb works like a server for a plant recipe management. If configured as Hmi (for a single station), it can work as either as a server or a client. The program can therefore file recipes on the PC's hard disk or retrieve them from the server.
In addition, any terminal, however small (e.g. 2x20 characters), can be used to carry out any operation on recipes residing in the Pcdb server. This allows Benassimpianti to offer its customers different levels of control, depending on their specific needs. Finally, thanks to MicroC indexing, it is possible to control a higher number of seasoning rooms, without having to rewrite the application software pr modify the hardware structure.

Benefits for end-users
According to Meris Dominici from Benassimpianti, Pcdb software offers many advantages to end-users. The seasoning process becomes more precise and hence production costs drop, and the climatic conditions of a certain environment can be easily reproduced.
The whole factory can be controlled from a single point, and when it is not supervised, it can always be monitored via Sms and remote control.
The system enables complete and precise data collection (on Cvs/Excel files), which is fundamental for compliance with Haccp standards.
On the onset of any anomalies, it is possible to reset it quickly thanks to a precise diagnosis. Benassimpianti's telesupport provides accurate maintenance and process assistance and allows you to update the software, guaranteeing a substantial reduction in operating times and costs.
Finally, as we have already mentioned, the plant can be expanded without having to develop new control software.