AS-i networks generally do not need to be continuously monitored. A specially developed modulation method guarantees robust data transfer and ensures maximum availability during operation, even under harsh environmental conditions. And the intelligent data protocol makes the entire system safe and insensitive to interference and external influences.

So why develop special diagnostic software for AS-Interface anyway? For Bihl+Wiedemann, there were two main arguments in favor of this: Firstly, such a solution allows the installation to be checked for any errors during acceptance of the system. Secondly, it not only supports troubleshooting in the event of a fault, but also provides concrete suggestions for solutions - for example, which slave needs to be replaced. It can also provide valuable services during recurring maintenance intervals.

Specifically, the aforementioned diagnostic software records information on voltage, current and symmetry and makes it possible, for example, to detect configuration, peripheral and telegram errors. And not only in standard AS-i circuits, but also in the safety area, i.e. with 'AS-i Safety at Work'. The diagnosis even works with several safety monitors linked together via 'Safe Link'. Safe Link is a safe link from Bihl+Wiedemann, which can be used to connect up to 31 gateways or safety monitors and therefore almost 2000 safe signals - even from different machines and system parts - in a simple way via Ethernet.

A particular advantage of the software is its ease of use. Even without special AS-i training, minor faults can be easily rectified - such as localizing and rectifying an earth fault. Suitable documents are also available on the network, for example, which users can access directly from the software.

Ring buffer facilitates troubleshooting

In concrete terms, the diagnosis works as follows: The user connects the laptop to the AS-i master on site or via the network, sets the monitoring duration and presses Start. In the case of a permanent error, only a short measurement is required. In order to find sporadic faults, it was previously possible to measure for up to 24 hours.

Status display during the test: All indicators are green - the test has not yet shown any errors.

© Bihl+Wiedemann

With the recent implementation of an optional ring buffer, the possible monitoring duration has been significantly extended. Almost every sporadic fault can now be found within a week. Users can now set the software's measurement duration accordingly. The ring buffer constantly overwrites itself and therefore always keeps the latest data - for the last 24 hours at most - available for evaluation. However, it is also possible to define shorter periods. For example, if you set the ring buffer to store only the data from the last half hour, you will receive less irrelevant data in the event of an error. This makes it easier to analyze the cause of the error.

At the end, the software not only reports 'network OK' or 'not OK'. The user also receives a detailed test report as a PDF. Here, the communication of all AS-i devices is evaluated individually. The three traffic light colors green, yellow and red symbolize the frequency of errors and the extent to which action is required.

The user receives even more information on safe communication in the network. Here, colored bars visualize whether and how the logical status of the respective components has changed over the set measurement duration. This means that correlations can often be identified at a glance - for example, whether the sporadic shutdown of a system component was triggered by a defective connected sensor and, more importantly, by which sensor. The shorter the set measurement duration, the easier it is to see even very short changes over time. Users who need help evaluating the diagnostic log can also send their diagnostic data to Bihl+Wiedemann support. They are able to evaluate the transmitted information in even greater detail.