roboglia.base.RegisterWithConversion

class RegisterWithConversion(factor=1.0, offset=0, sign_bit=None, **kwargs)

Bases: roboglia.base.register.BaseRegister

A register with an external representation that is produced by using a linear transformation:

external = (internal - offset) / factor
internal = external * factor + offset

The RegisterWithConversion inherits all the paramters from BaseRegister and in addition includes the following specific parameters that are used when converting the data from internal to external format.

Parameters

• factor (float) – A factor used for conversion. Defaults to 1.0.

• offset (int) – The offset for the conversion; defaults to 0 (int)

• sign_bit (int or None) – If a number is given it means that the register is “signed” and that bit represents the sign. Bits are numbered from 1 meaning that if sign_bit is 1 the less significant bit is used and if we have a 2 bytes register the most significant bit would be 16. The convention is that numbers having 0 in this bit are positive and the ones having 1 are negative numbers.

• Raises – KeyError: if any of the mandatory fields are not provided ValueError: if value provided are wrong or the wrong type

__init__(factor=1.0, offset=0, sign_bit=None, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

property factor

The conversion factor for external value.

property offset

The offset for external value.

property sign_bit

The sign bit, if any.

value_to_external(value)

The external representation of the register’s value.

Performs the translation of the value according to:

external = (internal - offset) / factor

value_to_internal(value)

The internal representation of the register’s value.

Performs the translation of the value according to:

internal = external * factor + offset

The resulting value is rounded to produce an integer suitable to be stored in the register.

__str__()

Representation of the register [name]: value.

property access

Register’s access mode.

property address

The register’s address in the device.

property clone

Indicates the register is a clone of another.

property default

The register’s default value in internal format.

property device

The device the register belongs to.

property int_value

Internal value of register, if a clone return the value of the main register.

property max_ext

The register’s maximum value in external format.

property maxim

The register’s maximum value in internal format.

property min_ext

The register’s minimum value in external format.

property minim

The register’s minimum value in internal format.

property name

Register’s name.

property order

Indicates the order of the data representartion; low-high (LH) or high-low (HL)

property range

Tuple with (minim, maxim) values in internal format.

property range_ext

Tuple with (minim, maxim) values in external format.

read()

Performs the actual reading of the internal value of the register from the device. Calls the device’s method to read the value of register.

property size

The regster’s size in Bytes.

property sync

Register is subject to a sync loop update.

property value

Provides the value of the register in external format. If the register is not marked for sync then it requests the device to perform a read in order to refresh the content of the register.

Returns

The value of the register in the external format. It invokes value_to_external() which can be overridden by subclasses to provide different representations of the register’s value (hence the any return type).

Return type

any

property word

Indicates if the register is an 16 bit register (True) or an 8 bit register.

write()

Performs the actual writing of the internal value of the register to the device. Calls the device’s method to write the value of register.