Shared Client Internals

Pure-computation and compatibility methods shared by Client and AsyncClient. Applications normally access these methods through one of the concrete clients.

Shared base for the sync Client and async AsyncClient.

Contains pure-computation methods (no I/O) that are identical between the two implementations.

class snap7.client_base.ClientMixin

Methods shared between Client and AsyncClient.

Every method here is pure computation — no socket or asyncio I/O. Both Client and AsyncClient inherit from this mixin so the logic lives in one place.

Subclasses must provide the following attributes (set in __init__):

host, local_tsap, remote_tsap, connection_type, session_password, pdu_length, connected, _exec_time, _last_error, _params, _on_operation, _operation_depth

error_text(error_code: int) → str

Get error text for error code.

Parameters:

error_code – Error code to look up

Returns:

Human-readable error text

get_exec_time() → int

Get last operation execution time.

Returns:

Execution time in milliseconds

get_last_error() → int

Get last error code.

Returns:

Last error code

get_param(param: Parameter) → int

Get client parameter.

Parameters:

param – Parameter number

Returns:

Parameter value

get_pdu_length() → int

Get negotiated PDU length.

Returns:

PDU length in bytes

get_pg_block_info(data: bytearray) → TS7BlockInfo

Get block info from raw block data.

Parameters:

data – Raw block data

Returns:

Block information structure

set_connection_params(address: str, local_tsap: int, remote_tsap: int) → None

Set connection parameters.

Parameters:

• address – PLC IP address

• local_tsap – Local TSAP

• remote_tsap – Remote TSAP

set_connection_type(connection_type: int) → None

Set connection type.

Parameters:

connection_type – Connection type (1=PG, 2=OP, 3=S7Basic)

set_param(param: Parameter, value: int) → int

Set client parameter.

Parameters:

• param – Parameter number

• value – Parameter value

Returns:

0 on success