Module configuration 

Configuration

Runtime environment variables

ExecutorConfig::from_env() reads these at startup:

Variable	Description	Default
ROS_DOMAIN_ID	ROS 2 domain ID	0
ZENOH_LOCATOR	Router address (tcp/…, udp/…, or tls/…)	tcp/127.0.0.1:7447
ZENOH_MODE	Session mode: client or peer	client
ZENOH_TLS_ROOT_CA_CERTIFICATE	Path to CA certificate (PEM)	—
ZENOH_TLS_ROOT_CA_CERTIFICATE_BASE64	Base64-encoded CA cert (bare-metal)	—

Buffer tuning (build-time)

Set these environment variables before cargo build. After changing a value, run cargo clean -p zpico-sys (or xrce-sys) to force a rebuild.

Zenoh backend (ZPICO_*):

Variable	Description	Posix	Embedded
ZPICO_FRAG_MAX_SIZE	Max reassembled message size	65536	2048
ZPICO_BATCH_UNICAST_SIZE	Max unicast batch before fragmentation	65536	1024
ZPICO_BATCH_MULTICAST_SIZE	Max multicast batch size	8192	1024
ZPICO_SUBSCRIBER_BUFFER_SIZE	Per-subscriber buffer in zenoh shim	1024	1024
ZPICO_SERVICE_BUFFER_SIZE	Per-service-server buffer in zenoh shim	1024	1024

XRCE-DDS backend (XRCE_*):

Variable	Description	Posix	Embedded
XRCE_TRANSPORT_MTU	Transport MTU (also sizes stream buffers)	4096	512
XRCE_BUFFER_SIZE	Per-entity static buffer size	1024	1024
XRCE_STREAM_HISTORY	Reliable stream history depth (>= 2)	4	4

Core (NROS_*, C API only):

Variable	Description	Default
NROS_EXECUTOR_MAX_HANDLES	Max handles in C API executor	16
NROS_MAX_SUBSCRIPTIONS	Max subscriptions	8
NROS_MAX_TIMERS	Max timers	8
NROS_MAX_SERVICES	Max services	4
NROS_MESSAGE_BUFFER_SIZE	Max buffer for subscription/service data	4096
NROS_MAX_PARAMETERS	Max parameters in parameter server	32

Example — increase zenoh defrag to 128 KB for large point clouds:

ZPICO_FRAG_MAX_SIZE=131072 cargo build --features rmw-zenoh,platform-posix