Canopen Communications; Minimum State Machine - Curtis 1356 Manual

3 — CANopen COMMUNICATIONS
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CANopen COMMUNICATIONS

The 1356 /1356P adheres to the industry standard CANopen communication
protocol and thus will easily connect into many CAN systems, including those
using the Curtis AC and Vehicle System controllers. Any CANopen-compatible
master can be programmed to control the 1356 /1356P.
The 1356 /1356P receives two incoming (MOSI) PDOs and responds with
two outgoing (MISO) PDOs. Dynamic mapping is available for the PDOs. All
programmable parameters and monitor parameters are accessible by standard
SDO transfer.
The time between incoming PDOs is monitored and if excessive, will
flag a fault. This allows the 1356 /1356P to know that the system is still under
master control. The 1356 /1356P also produces Heartbeat and Error messages,
which is the CiA-preferred safety and security method.

MINIMUM STATE MACHINE

The 1356 /1356P will run the CANopen minimum state machine as defined
by CiA. The CANopen minimum state machine has four defined states: Ini-
tialization, Pre-Operational, Operational, and Stopped.
Power-On
Reset
Initialization
Transmit
Pre-Operational
Operational
When the 1356 /1356P powers up, it goes to the Initialization state; this is
also known as the Boot-up state. No CAN communications from the 1356 /1356P
are transmitted in this state although the 1356 /1356P listens to the CAN bus.
When the 1356 /1356P has completed its startup and self-tests, it issues an ini-
tialization heartbeat message and automatically goes to the Pre-Operational state.
In the Pre-Operational state, the 1356 /1356P can receive and respond to
SDOs and NMT commands, and will send its heartbeat. It will not receive or
send PDOs (unless PDO-MISO cyclic transmitting is enabled). After receiving
an Operational State NMT command, the 1356 /1356P will enter the Opera-
tional state (full normal operation).
In the Operational state, the 1356 /1356P will start receiving and respond-
ing to PDOs and process all other necessary CANopen messages.
Curtis 1356/1356P CAN Expansion Module Manual,
Reset
Module
Reset
Communication
Boot-up
Stopped
Rev. A