Automotive: Control of Communication

The car manufacturer Audi chose the diagnostics and monitoring solution from Softing Industrial Automation for a German site. The main benefits? The quality of the PROFINET communication both for network acceptance testing and during normal operation

by Vittoria Ascari

The PROFINET communication standard for the diagnostics and management of automation networks is ideally suited for acceptance testing and continuous monitoring of the network.
In addition, it provides functionality to efficiently carry out maintenance tasks. While primarily used in new projects, it can also be integrated seamlessly into existing facilities.
One of the users of the PROFINET solution is the car manufacturer Audi at their Neckarsulm site in Germany.

From the component parts to the complete body-in-white
The body manufacturing production planning department is responsible for the plant technology of new body manufacturing facilities. These cover all production steps from the manufacture of the component parts to the assembly of the complete body-in-white. For this purpose, PROFINET was introduced in 2006 and has been employed ever since in linear, star, and ring network topologies using Conformance Class C (PROFINET IRT) devices.
The automation networks are integrated into the corporate network using SNMP services and a defined transfer interface. Besides PLCs, robots and, partly also process devices are equipped with PROFINET controller functionality.
As the associated project engineering tools typically only support the diagnostics of PROFINET devices assigned to them, a central overview of the network state of the entire plant is lacking.

A consistent use in the various project phases of the plant
A central requirement to the PROFINET diagnostics solution to be used is its consistent use in the various project phases of the plant. During the installation phase, all components are built into the plant as defined in the specification. In the maintenance phase, the operation of the facility is continually monitored so that conditions such as device errors or an additional communication load on individual ports can be detected. In the event of a fault, it is necessary to locate its cause quickly so that a suitable maintenance action. The final assembly department performs all operations on the painted car body, to the final inspection and factory acceptance test. Here, primarily flat PROFINET structures with a central network connection of the PC to the switch are used. For the A4 and A6 series, final assembly relies on approximately 60 PROFINET networks, separated from each other by firewalls. A diagnostics and monitoring solution which specifically meets maintenance requirements, which can be integrated into the maintenance workflows, and which takes some load off the limited resources had to be built into the existing networks. Great importance is attached to the use of tools which are independent of the PROFINET components employed, and lend themselves to integration into projects and existing networks while the facility is in operation. What is more, the integration must neither require additional components, such as database computers, nor installation work, and must make do with the limited space in the control cabinet.

All diagnostics, system and device information are provided
Meeting the Audi needs requires a diagnostics and monitoring solution which provides all diagnostics, system, and device information, permanently records monitored actual conditions and enables access to history data from the entire network. This way, all required information is available in case of need. Critical sub-functions of the solution employed are a topology view that allows a quick localization of failed devices, the display of detail information for the components in use, including inventory and stock details, as well as the detection of intermittent communication errors. The departments opted for the diagnostics and monitoring solution from Softing Industrial Automation, which is based on two components. The TH LINK PROFINET product provides secure access to the individual PROFINET networks, and monitors the communication and device status on the network based on a specific diagnostics algorithm. This algorithm not only performs passive monitoring of the data traffic, but also actively uses the diagnostics options provided by PROFINET and general Ethernet protocols. This allows to identify the devices on the network, supply device diagnostics information including network statistics, detect communication errors, and determine the network topology. The TH SCOPE monitoring software gathers all data at a central location, and presents the consolidated data in a graphical user interface. The presentation of the results is geared to a consistent use across the various project phases, and in particular supports the completion of maintenance measures.

A straightforward and quick determination of error causes
Audi has included this solution as an integral part of all new body manufacturing projects managed by the Neckarsulm site. In addition, the diagnostics and monitoring solution is gradually integrated into existing final assembly facilities. “A major benefit for Audi is the consistent use of the diagnostics and monitoring solution, from installation to daily operation. This allows us for example to do reference measurements for a comparison of the acceptance test situation to the current network status and quickly spot any alterations” concludes Felix Niederbacher, technical manager for automation engineering standardization in the body manufacturing production planning department. The TH LINK PROFINET and TH SCOPE products support Audi with ensuring a consistent high quality of the PROFINET communication both for network acceptance testing and during normal operation.
Due to the straightforward and quick determination of error causes after the detection of erratic behavior, a constantly higher availability of the facilities is achieved.
The possibility to connect an entire network including its subnetworks by means of a single TH LINK PROFINET device contributes to a positive cost-benefit ratio. Another decisive factor is the option to retrofit existing facilities without stopping normal operation.