Manual node discovery

This script showcases how the client can discover nodes and query their description manually.

from pyaseba.client import Client

We set up the client to not discover nodes automatically

client = Client(automatic_query=False, ping_period_ms=0)
connection = client.connect("tcp", port=33333)
connection

1

With this configuration, waiting for nodes will not discover them

client.wait_nodes(wait_ms=500)

{}

Instead, we need to first manually scan for node IDs

scan = client.scan(wait_ms=500)
scan

{1: {0}}

and then query them for a description

for target, node_ids in scan.items():
    for node_id in node_ids:
        desc = client.query_description(node_id=node_id, wait_ms=500)
        print(f"Node {node_id}: {desc}")

Node 0: Description(name='SimpleNode', protocol_version=9, variables={'_productId': (34, 1), 'args': (2, 32), 'counter': (35, 1), 'id': (0, 1), 'source': (1, 1), 'value': (36, 1)}, local_events={'event': 'emitted at each control step after incrementing counter'}, user_events={}, functions={'duplicate': ('duplicates the input', [('input', 1), ('result', 1)]), 'square': ('set value to the square of the input', [('input', 1)])})

Once we have received them, IDs and descriptions are accessible like for automatically discovered nodes.

client.descriptions

{1: {0: Description(name='SimpleNode', protocol_version=9, variables={'_productId': (34, 1), 'args': (2, 32), 'counter': (35, 1), 'id': (0, 1), 'source': (1, 1), 'value': (36, 1)}, local_events={'event': 'emitted at each control step after incrementing counter'}, user_events={}, functions={'duplicate': ('duplicates the input', [('input', 1), ('result', 1)]), 'square': ('set value to the square of the input', [('input', 1)])})}}

client.close()