Class: TcpTransport

TCP transport for network-attached thermal label printers.

Targets the JetDirect raw socket (port 9100) by default. Accumulates incoming bytes across data events so read(n) hands callers a pull-based API over a stream socket.

Implements

• Transport

Accessors

connected

Get Signature

get connected(): boolean;

Whether the transport is currently connected.

Returns

boolean

Implementation of

Transport.connected

Methods

close()

close(): Promise<void>;

Close the connection.

Always safe to call multiple times. Always await the result.

Returns

Promise<void>

Implementation of

Transport.close

---

read()

read(length: number, timeout?: number): Promise<Uint8Array>;

Read bytes from the printer.

Buffers until length bytes are available or the timeout fires.

BLE implementations: there is no "read N bytes" primitive in BLE. Implementations must buffer incoming GATT notifications internally and satisfy read() calls from that buffer. Document this in your transport class — every BLE implementation must handle buffering consistently so drivers get the same pull-based API on every transport.

Parameters

Parameter	Type
length	number
timeout?	number

Returns

Promise<Uint8Array>

Throws

TransportTimeoutError on timeout.

Throws

TransportClosedError if the transport is closed mid-read.

Implementation of

Transport.read

---

write()

write(data: Uint8Array): Promise<void>;

Send bytes to the printer.

Parameters

Parameter	Type
data	Uint8Array

Returns

Promise<void>

Implementation of

Transport.write

---

connect()

static connect(
   host: string, 
   port?: number, 
timeout?: number): Promise<TcpTransport>;

Connect to a raw TCP printer port.

Parameters

Parameter	Type	Default value	Description
host	string	undefined	IP address or hostname.
port	number	DEFAULT_PORT	TCP port (default 9100).
timeout?	number	undefined	Connection timeout in ms (default 5000). On expiry the returned promise rejects with TransportError (not TransportTimeoutError, which the contracts reserve for read timeouts).

Returns

Promise<TcpTransport>