Protocols
Links
Apache 2.0 licensed JNI library for accessing raw IPv4 and IPv6 sockets. Might be the ideal starting point for implementing protocols below TCP & UDP. https://www.savarese.org/software/rocksaw/
Links to different WireShark captures: https://github.com/automayt/ICS-pcap
BACNet
Used in the building automation sector. http://www.bacnet.org/Addenda/Add-135-2008t.pdf
AKA: ISO 16484-5: The official specification can be purchased here: https://www.iso.org/standard/71935.html
IEC 61850
Used by the IDS SAS (station automation system)
German norm: DIN EN 60870 The official specification can be purchased here: https://www.beuth.de/de/norm/din-en-60870-5-104/100426613