ABBCompact control system replaces PLCs Comfortable, more efficient integration of package units using AC 700F

The AC 700F controller increases the scalability of the 

compact control system Freelance 800F towards very 

small applications with only a few I/Os and closes the 

gap between PLCs (programmable logic controllers) 

and complex process control systems. It is suitable 

for smallest applications with about 10 to 250 I/Os per 

controller and thus opens up additional application areas 

for the Freelance 800F control system, which is suitable 

for both small and also medium-sized projects with several thousand signals. Comfortable, advanced functions 

of control systems are now also available for very small 

applications – and all at a very reasonable price. The 

AC 700F controller offers a large number of advantages 

compared to a standard PLC with visualization from thirdparty vendors. The projects on the following pages show 

these advantages and the various application areas for 

the AC 700F controller. 

Thanks to the compact control system Freelance 800F and its 

AC 700F controller it is now possible for smaller automation 

solutions, which to date have been dominated by PLCs, to 

benefit from the advantages of process control systems, 

particularly in the process industry. There is a wide range of 

use in many industries including chemicals, petrochemicals, 

oil and gas, metals, cement production, glass production, etc.

The AC 700F controller can be integrated into existing Freelance

800F systems in the same way as the AC 800F controller. 

In contrast to PLCs, the AC 700F controller offers all of the 

advantages of the compact control system. Important for 

engineering and maintenance: A single engineering tool for 

all tasks: Control Builder F. 

DigiVis, the visualization tool, makes operation easy, structured

and intuitive. Pre-engineered components such as faceplates, 

module diagnostics, event lists, the alarm line, trend displays 

and automatically generated SFC (Sequential Function Chart) 

displays play a key role in this regard. The use of predefined, 

field proven libraries including faceplates significantly eases 

the transparency, readability and adaptability of the application

and substantially increases security. The advanced diagnostic 

options and improved alarm handling allows cost cutting in 

the operation and maintenance phase and asset availability 

can be enhanced. This substantially increases the economic 

efficiency of the entire plant. 

AlzChem GmbH in Trostberg, a subsidiary of Evonik Industries 

AG, produces specialty chemicals products with a wide range 

of uses. These chemicals are used, for example, in the production of crop protection products, pigments, dyes, pharmaceuticals and polymers. 

In the past, an inverted filter centrifuge in a system for extracting natural substances was PLC-controlled at AlzChem GmbH.

The program code for the PLC, a standard program from the 

manufacturer, was not transparent and needed specialists to 

make changes. The program was not intuitive and diagnostic 

analyses were only available to a very limited extent. In order 

to simplify programming and to optimize the process control, 

AlzChem thus decided to use the AC 700F controller. This replaced the PLC and was integrated into the existing Freelance 

800F system without any problems. 

This offers several advantages for AlzChem: The use of one 

single engineering tool to configure the entire system simplifies

engineering and saves a significant amount of time during 

commissioning. After transferring the program the system is 

easy to understand and maintenance is simpler.

During the operating and maintenance phase, the wide range 

of diagnostic options (sequence control-, hardware -, interlock 

diagnostics), the intuitive graphical user interface and mature 

alarm and report management allow costs to be cut. This 

reduces downtime of the application and cuts maintenance 

Project: System for extracting natural substances, 

AlzChem GmbH, Trostberg, Germany 

Industry: Chemicals

expenditures. All this improves the efficiency of the entire 

system and the slightly higher acquisition costs compared to 

a PLC amortize within a very short time.

Hartmut Rohner, Head of Electrical Systems, Instrumentation 

and Control at AlzChem, is particularly impressed by the simple

and clear handling of the AC 700F controller and the Freelance

800F system. “It is easy for anyone to learn how to operate 

the software and hardware. In contrast, it was practically impossible to understand the standard program supplied by the 

manufacturer together with the centrifuge.” Mr. Rohner also 

sees clear advantages over other systems when it comes to 

maintenance and faultfinding. Whereas with other manufacturers faultfinding is only possible using a handheld device in 

the field, Freelance 800F provides extensive analysis options 

right in the control room. “Now I look at the status and can 

see straight away where the error is. That is not possible that