Variables

SECS variable types.

class secsgem.secs.variables.F4(value=None, count=-1)

Secs type for 4 byte float data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.F8(value=None, count=-1)

Secs type for 8 byte float data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.I1(value=None, count=-1)

Secs type for 1 byte signed data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.I2(value=None, count=-1)

Secs type for 2 byte signed data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.I4(value=None, count=-1)

Secs type for 4 byte signed data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.I8(value=None, count=-1)

Secs type for 8 byte signed data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.JIS8(value='', count=-1)

Secs type for string data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.U1(value=None, count=-1)

Secs type for 1 byte unsigned data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.U2(value=None, count=-1)

Secs type for 2 byte unsigned data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.U4(value=None, count=-1)

Secs type for 4 byte unsigned data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.U8(value=None, count=-1)

Secs type for 8 byte unsigned data.

Parameters:

• value – initial value

• count – number of items this value

class secsgem.secs.variables.Array(data_format, value=None, count=-1)

List variable type. List with items of same type.

static get_format(data_format, showname=False)

Get the format of the variable.

Parameters:

• data_format – internal data definition/sample

• showname – show the name of the variable

Returns:

string representation of the function

append(data)

Append data to the internal list.

Parameters:

data – list item to add

set(value)

Set the internal value to the provided value.

Parameters:

value – new value

get()

Return the internal value.

Returns:

internal value

encode()

Encode the value to secs data.

Return type:

bytes

Returns:

encoded data bytes

decode(data, start=0)

Decode the secs byte data to the value.

Parameters:

• data – encoded data bytes

• start – start position of value the data

Returns:

new start position

class secsgem.secs.variables.Base(value=None)

Base class for SECS variables.

Due to the python types, wrapper classes for variables are required. If constructor is called with Base or subclass only the value is copied.

set(value)

Set the internal value to the provided value.

Parameters:

value – new value

encode_item_header(length)

Encode item header depending on the number of length bytes required.

Parameters:

length – number of bytes in data

Returns:

encoded item header bytes

decode_item_header(data, text_pos=0)

Encode item header depending on the number of length bytes required.

Parameters:

• data – encoded data

• text_pos – start of item header in data

Return type:

tuple[int, int, int]

Returns:

start position for next item, format code, length item of data

property is_dynamic: bool

Check if this instance is Dynamic or derived.

property preferred_type

Get the preferred type for this variable.

class secsgem.secs.variables.Binary(value=None, count=-1)

Secs type for binary data.

supports_value(value)

Check if the current instance supports the provided value.

Parameters:

value – value to test

Return type:

bool

Returns:

True if the value is supported, False otherwise

set(value)

Set the internal value to the provided value.

Parameters:

value – new value

get()

Return the internal value.

Returns:

internal value

encode()

Encode the value to secs data.

Return type:

bytes

Returns:

encoded data bytes

decode(data, start=0)

Decode the secs byte data to the value.

Parameters:

• data – encoded data bytes

• start – start position of value the data

Returns:

new start position

class secsgem.secs.variables.Boolean(value=None, count=-1)

Secs type for boolean data.

supports_value(value)

Check if the current instance supports the provided value.

Parameters:

value – value to test

Return type:

bool

Returns:

True if the value is supported, False otherwise

set(value)

Set the internal value to the provided value.

Parameters:

value – new value

get()

Return the internal value.

Returns:

internal value

encode()

Encode the value to secs data.

Return type:

bytes

Returns:

encoded data bytes

decode(data, start=0)

Decode the secs byte data to the value.

Parameters:

• data – encoded data bytes

• start – start position of value the data

Returns:

new start position

class secsgem.secs.variables.Dynamic(types, value=None, count=-1)

Variable with interchangable type.

property preferred_type

Get the preferred type.

set(value)

Set the internal value to the provided value.

In doubt provide the variable wrapped in the matching secsgem.secs.variables.Base class, to avoid confusion.

Parameters:

value – new value

Example

>>> import secsgem.secs
>>>
>>> var = secsgem.secs.variables.Dynamic([secsgem.secs.variables.String,
...                                       secsgem.secs.variables.U1])
>>> var.set(secsgem.secs.variables.U1(10))
>>> var
<U1 10 >

If no type is provided the default type is used which might not be the expected type.

get()

Return the internal value.

Returns:

internal value

encode()

Encode the value to secs data.

Return type:

bytes

Returns:

encoded data bytes

decode(data, start=0)

Decode the secs byte data to the value.

Parameters:

• data – encoded data bytes

• start – start position of value the data

Returns:

new start position

property is_dynamic: bool

Check if this instance is Dynamic or derived.

class secsgem.secs.variables.List(data_format, value=None)

List variable type. List with items of different types.

static get_format(data_format, showname=False)

Get the format of the variable.

Returns:

string representation of the function

static get_name_from_format(data_format)

Generate a name for the passed data_format.

Parameters:

data_format – data_format to get name for

Returns:

name for data_format

set(value)

Set the internal value to the provided value.

Parameters:

value – new value

get()

Return the internal value.

Returns:

internal value

encode()

Encode the value to secs data.

Return type:

bytes

Returns:

encoded data bytes

decode(data, start=0)

Decode the secs byte data to the value.

Parameters:

• data – encoded data bytes

• start – start position of value the data

Returns:

new start position

class secsgem.secs.variables.String(value='', count=-1)

Secs type for string data.

Parameters:

• value – initial value

• count – number of items this value