There are multiple available examples of protocol definitions that use CommsDSL schema files and commsdsl2comms code generator to generate relevant code.

Synthetic Demo Protocols

cc.demo1.commsdsl - Demo protocol to demonstrate definition of various fields as well as simple protocol framing. The generated code can be viewed at cc.demo1.generated.
cc.demo2.commsdsl - Demo protocol to demonstrate protocol versioning, where every message reports protocol version in its transport frame. The generated code can be viewed at cc.demo2.generated.
cc.demo3.commsdsl - Demo protocol to demonstrate protocol versioning, where one “connect” message reports protocol version for all the subsequent messages. The generated code can be viewed at cc.demo3.generated.

Every synthetic demo protocol also provides 2 example applications: server and client, which exchange messages.

Real Life Open Protocols

cc.mqtt311.commsdsl - Defines MQTT v3.1.1 protocol, where message ID shares the same byte with extra flags, that may define existence of the fields in message payload as well as influence how message needs to be processed. The protocol definition also contains snippets of custom code that are injected by the commsdsl2comms into the generated one. The generated code can be viewed at cc.mqtt311.generated.
cc.mqtt5.commsdsl - protocol. Similar to v3.1.1, but also adds a heterogeneous list of various properties. The generated code can be viewed at cc.mqtt5.generated.
cc.mqttsn.commsdsl - Defines MQTT-SN protocol, where field of remaining length of the message can have either 1 or 3 bytes length, depending on the value it contains. The generated code can be viewed at cc.mqttsn.generated.
cc.ublox.commsdsl - Defines UBX protocol used by various u-blox GPS receivers. The protocol itself is quite complex with hundreds of messages. It uses custom checksum calculation algorithms and injects multiple code snippets to fix incorrect or incomplete functionality available by default. The generated code can be viewed at cc.ublox.generated.