UMAX140610. LIN
– J1939 CAN Protocol Converter with PWM Output. Version 1
Page: 11-81
Each function block is absolutely independent and has its own set of configuration parameters,
aka setpoints. The configuration parameters can be viewed and changed through CAN bus
using Axiomatic Electronic Assistant
®
(EA) software.
LIN interface is presented by the
LIN Signal
function blocks and function blocks controlling
sending and receiving of the LIN signals. Each
LIN Signal
function block has one signal input
and one signal output. When the
LIN Signal
functional block transmits data on the LIN bus, it
reads data from the signal input. When it receives data from the LIN bus, the data is written to
the signal output.
J1939 CAN interface is presented by the
CAN Receive, CAN Transmit
and
Miscellaneous
function blocks. The
CAN Receive
functional blocks are used to receive CAN signals
transmitted on the CAN bus. They have one signal output, which is updated once the signal is
received. The
CAN Transmit
function blocks are used to transmit CAN signals on the CAN
bus. Each CAN message can hold up to five individual CAN output signals, which receive data
from five signal inputs.
The converter has a PWM output, it can be configured by the
PWM Output
block. It can take
three input signals for 3 different uses: Command, Enable or Override. It will be discussed in
more detail later. For data processing, when required, the unit can use
Lookup Table,
Programmable Logic or Math Function
blocks. They take two input signals and combine them
together in one signal output using different functions. They will be described in more detail in
further sections.
The converter also has a
Constant Data
function block containing five discrete constant output
signals and five continuous constant output signals.
3.1 Function Block Signals
The converter function blocks can communicate with each other through signal inputs and
outputs. Each signal input can be connected to any signal output using an appropriate
configuration parameter. There is no limitation on the number of signal inputs connected to a
signal output.
When a signal input is connected to a signal output, data from the signal output of one function
block is available on the signal input of another function block.
Depending on the signal type, the function block signal output can be either
Discrete
or
Continuous
. The function block signal input, receiving the output signal, can be:
Undefined
,
Discrete
or
Continuous.
The
Undefined
input type is reserved for a disconnected input, while:
Discrete
and
Continuous
input types present inputs receiving discrete and continuous signals,
respectively.
3.1.1 Undefined Signal
The
Undefined
signal type is used to present a no-signal condition in signal data or to specify
that the signal input is not connected (not used).
3.1.2 Discrete Signal
The
Discrete
signal type is used to present a discrete signal that has a finite number of states
in signal data or to specify that the signal input or output is communicating this type of signals.
