Malcom: https://github.com/idaholab/Malcolm
EmberOT OT PCAP Analyzer: https://www.emberot.com/ot-pcap-analyzer
Industrial Control Systems Network Protocol Parsers (ICSNPP): https://github.com/cisagov/ICSNPP
RunZero Community Edition: https://www.runzero.com/pricing/
Network Miner (supports Modbus, IEC-104, and hardware from ABB, Allen-Bradley, Modicon, Moxa, Phoenix Contact and Siemens): https://www.netresec.com/?page=Networkminer
GRASSMARLIN: https://github.com/nsacyber/GRASSMARLIN