TelnetServerDevice¶

class dvg_devices.BaseDevice.TelnetServerDevice(name='Dev_1', long_name='Telnet Server Device')[source]¶

This class provides blocking I/O methods for a telnet server device by wrapping the telnetlib3 library.

The following functionality is offered:

I/O methods: readline(), write(), query().

Instances of this class will tie in nicely with dvg_qdeviceio.QDeviceIO.

Parameters:	long_name (`str`, optional) – Long display name of the device in a general sense. E.g., “Wemos ESP32-S3”. Default: “Telnet Server Device” name (`str`, optional) – Short display name for the device. E.g., “ESP32” or “blinker”. Default: “Dev_1”

Example:

from dvg_devices.BaseDevice import TelnetServerDevice

dev = TelnetServerDevice()
dev.connect(host="10.10.100.2", port=23)
success, reply = dev.query("My query command")

Attributes:

long_name¶

Long display name of the device in a general sense. E.g, “Wemos ESP32-S3”.

Type:	`str`

name¶

Short display name for the device. E.g., “ESP32” or “blinker”.

Type:	`str`

telnet_settings¶

Dictionary of keyword arguments to be passed directly to telnetlib3.sync.TelnetConnection when calling method connect().

Default: {“timeout”: 4, “encoding”: “utf8”,}

Type:	`dict`

conn¶

Will be set to a telnetlib3.sync.TelnetConnection instance when a connection has been established. Otherwise: None.

Type:	`telnetlib3.sync.TelnetConnection` \| `None`

is_alive¶

Is the connection alive? I.e., Can we communicate?

Type:	`bool`

Methods¶

TelnetServerDevice.readline(raises_on_timeout: bool = False) → Tuple[bool, Optional[Union[str, bytes]]][source]¶

Listen to the telnet server for incoming data. This method is blocking and returns when a full line has been received or when the read timeout has expired.

Parameters:

raises_on_timeout (bool, optional) – Should an exception be raised when a read timeout occurs?

Default: False

Returns:

success (bool):: True if successful, False otherwise.
reply (str | bytes, None):: Reply received from the device. None if unsuccessful.

Return type:

tuple

TelnetServerDevice.write(msg: str) → bool[source]¶

Send a message to the telnet server.

Parameters:	msg (`str`) – ASCII string to be sent to the serial device.
Returns:	True if successful, False otherwise.

TelnetServerDevice.query(msg: str) → Tuple[bool, Optional[Union[str, bytes]]][source]¶

Send a message to the telnet server and subsequently read the reply.

Parameters:	msg (`str`) – ASCII string to be sent to the telnet server.
Returns:	success (`bool`): True if successful, False otherwise. reply (`str` \| `bytes` \| `None`): Reply received from the device. `None` if unsuccessful.
Return type:	`tuple`

TelnetServerDevice.close(ignore_exceptions=False)[source]¶: Close the telnet connection.