Run Multiple Transports Simultaneously

This guide shows how to expose a fastcs driver through multiple protocols at once.

Basic Setup

Pass a list of transports to FastCS:

from fastcs.control_system import FastCS
from fastcs.transports import (
    EpicsCATransport,
    EpicsIOCOptions,
    GraphQLTransport,
    RestTransport,
)

controller = MyController()

fastcs = FastCS(
    controller,
    [
        EpicsCATransport(epicsca=EpicsIOCOptions(pv_prefix="DEVICE")),
        RestTransport(),
        GraphQLTransport(),
    ]
)
fastcs.run()

All transports run concurrently, exposing the same controller API.

Available Transports

Transport	Protocol	Install Extra	Primary Use Case
EpicsCATransport	EPICS Channel Access	fastcs[epicsca]	Control system integration
EpicsPVATransport	EPICS PV Access	fastcs[epicspva]	Modern EPICS with structured data
TangoTransport	Tango	fastcs[tango]	Tango control system
RestTransport	HTTP REST	fastcs[rest]	Web applications, debugging
GraphQLTransport	GraphQL	fastcs[graphql]	Flexible queries, web clients

Install extras as needed:

pip install "fastcs[epicsca,rest,graphql]"

Transport Configuration

Each transport has its own options:

EPICS Channel Access

from pathlib import Path
from fastcs.transports import (
    EpicsCATransport,
    EpicsDocsOptions,
    EpicsGUIOptions,
    EpicsIOCOptions,
)

epics_ca = EpicsCATransport(
    epicsca=EpicsIOCOptions(pv_prefix="DEVICE"),
    gui=EpicsGUIOptions(
        output_path=Path(".") / "device.bob",
        title="Device Control",
    ),
    docs=EpicsDocsOptions(
        output_path=Path(".") / "device.csv",
    ),
)

EPICS PV Access

from fastcs.transports import EpicsPVATransport, EpicsIOCOptions

epics_pva = EpicsPVATransport(
    epicspva=EpicsIOCOptions(pv_prefix="DEVICE"),
)

REST

from fastcs.transports import RestTransport
from fastcs.transports.rest import RestServerOptions

rest = RestTransport(
    rest=RestServerOptions(
        host="0.0.0.0",
        port=8080,
        log_level="info",
    )
)

GraphQL

from fastcs.transports import GraphQLTransport
from fastcs.transports.graphql import GraphQLServerOptions

graphql = GraphQLTransport(
    graphql=GraphQLServerOptions(
        host="localhost",
        port=8081,
    )
)

Tango

from fastcs.transports import TangoTransport, TangoDSROptions

tango = TangoTransport(
    tango=TangoDSROptions(
        device_name="test/device/1",
    ),
)

EPICS CA + PVA Together

Run both EPICS protocols simultaneously:

from pathlib import Path

from fastcs.transports import (
    EpicsCATransport,
    EpicsGUIOptions,
    EpicsIOCOptions,
    EpicsPVATransport,
)

fastcs = FastCS(
    controller,
    [
        EpicsCATransport(
            epicsca=EpicsIOCOptions(pv_prefix="DEVICE"),
            gui=EpicsGUIOptions(output_path=Path(".") / "device.bob"),
        ),
        EpicsPVATransport(
            epicspva=EpicsIOCOptions(pv_prefix="DEVICE"),
        ),
    ]
)

Both transports share the same PV prefix and expose identical PVs.

YAML Configuration

When using the launch() framework, configure transports in YAML.

See Using the Launch Framework for details.