Mission Database

The Mission Database API provides methods for reading the entries in a Yamcs Mission Database (MDB). An MDB groups telemetry and command definitions for one or more space systems. The MDB is used to:

  • Instruct Yamcs how to process incoming packets
  • Describe items in Yamcs Archive
  • Instruct Yamcs how to compose telecommands

Space systems form a hierarchical multi-rooted tree. Each level of the tree may contain any number of definitions. These break down in:

  • parameters
  • containers
  • commands
  • algorithms

Entries in the Space system are addressable via a qualified name that looks like a Unix file path. Each segment of the path contains the name of the space system node, the final path segment is the name of the entry itself.

For example, in an MDB that contains these parameter entries:

└── YSS
    └── SIMULATOR
        ├── BatteryVoltage1
        └── BatteryVoltage2

we find two space systems /YSS and /YSS/SIMULATOR and two parameter entries /YSS/SIMULATOR/BatteryVoltage1 and /YSS/SIMULATOR/BatteryVoltage2.

Some MDB entries may also define an alias. An alias is a unique name to address the entry under a custom namespace (unrelated to XTCE space systems).

When it comes to addressing entries via this client, it is possible to provide either the fully-qualified XTCE name in the format /YSS/SIMULATOR/BatteryVoltage1 or an alias in the format NAMESPACE/NAME.

Reference

Snippets

Create an MDBClient for a specific instance:

from yamcs.client import YamcsClient

client = YamcsClient('localhost:8090')
mdb = client.get_mdb(instance='simulator')

Print all space systems:

for space_system in mdb.list_space_systems():
    print(space_system)

Print all parameters of type float:

for parameter in mdb.list_parameters(parameter_type='float'):
    print(parameter)

Print all commands:

for command in mdb.list_commands():
    print(command)

Find a parameter by qualified name or alias:

p1 = mdb.get_parameter('/YSS/SIMULATOR/BatteryVoltage2')
print('Via qualified name:', p1)

p2 = mdb.get_parameter('MDB:OPS Name/SIMULATOR_BatteryVoltage2')
print('Via domain-specific alias:', p2)