import attr
from ..factory import target_factory
from .common import Resource
from .base import SerialPort
[docs]
@target_factory.reg_resource
@attr.s(eq=False)
class ModbusRTU(SerialPort, Resource):
"""This resource describes Modbus RTU instrument.
Args:
port (str): tty the instrument is connected to, e.g. '/dev/ttyUSB0'
speed (int): optional, default is 115200
address (int): slave address on the modbus, e.g. 16
timeout (float): optional, timeout in seconds. Default is 0.25 s
"""
address = attr.ib(default=None, validator=attr.validators.instance_of(int))
timeout = attr.ib(default=0.25,
validator=attr.validators.instance_of(float))
[docs]
def __attrs_post_init__(self):
super().__attrs_post_init__()
if self.port is None:
raise ValueError("ModbusRTU must be configured with a port")
if self.address is None:
raise ValueError("ModbusRTU must be configured with an slave address")