TIA failed to discover vPLC

Products

• VMware NSX

Issue/Introduction

Industrial vSwitch (IvS) is used for manifacturing use case. There are many IO hardware devices in a automotive fatory, and virtual Programmable Logic Controller (vPLC) controls the IO devices. For the communication between vPLC and IO devices, low latency and reliable industrial ethernet Profinet is required. In addition to vPLC and IO devices, there is a management system for vPLCs. Currently IvS manifacturing solution support two vPLC vendors, Siemens and Codesys. Siemens management system is called Totally Integrated Automation (TIA). TIA discovers vPLC in the Profinet network using DCP (Discovery and Configuration Protocol).

This article is about the case that TIA failed to discover the vPLC.

 

Environment

4.2.x

Resolution

As a first step, please ensure that the network interface for TIA and vPLCs that are on the same NSX segment (VLAN). 
(Note: If a TIA runs on different ESXi hosts as the vPCL, the host does not always have a IvS configuration. In this case the IvS does not show any IvS statistics.)

Next, trace the DCP tx packets from TIA to a multicast MAC address by follwoing the step below.

 - Login to the ESXi Host where TIA VM is running via SSH
 - Run the command and find the switch port id of the TIA vm by running command net-stats -l. (look for switch port id by the ClientName (VM name))

 net-stats -l

 - Capture packet coming from TIA tx switch port to the multicast MAC address

 $pktcap-uw --switchport <Port ID> --dir 1 --capture VnicTx --dstmac <Multicasst MAC address>

The terminal will wait without any activity or packet dumps. Log in to TIA and check the Ethernet interface connected to the IvS. If the interface is down, disable/enable may fix the problem. If it does not, go to the TIA or/and vPLC VM and disconnect/reconnect their Profinet interface.

Login to the TIA portal and trigger the vPLC discovery. Watch for the packet discovery packet immediately after clicking “Update accessible devices.” If there is no packet, then check the network configuration. If there is a packet then go to the vPLC host and verify the rx packet at that switch port