When trying to commission a device with an Anybus-IC for PROFINET interface, it can take a long time until it is detected by powerful PLCs like the Siemens S7-1500 series. This article explains why this may happen and how to remedy the issue.
Anybus-IC for PROFINET, article number AB6005
Powerful PLCs like the Siemens S7-1500 series take a long time to detect devices equipped with an Anybus-IC for PROFINET (AB6005).
In large PROFINET networks in which many devices are not powered on or not even connected, it can happen that DCP (Discovery and Configuration Protocol) commands for the device search are sent out in a burst so quickly that the AB6005 cannot keep up with it. The DCP frames run into a waiting loop that may even overflow at some point.
The problem should disappear as soon as the PLC has established a connection with all devices in the network and thus sends out fewer search telegrams.
It can be beneficial to deactivate those devices which are not currently needed in the PROFINET network for the following reasons.
- The number of DCP commands is reduced because the deactivated devices are no longer searched for
- Missing devices generate errors in the PLC logs and on the LEDs. This does not apply to deactivated devices
This deactivation (as well as reactivation) can be done via the function D_ACT_DP.