3: Canopen Communications; Minimum State Machine - Curtis 1353 User Manual

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The 1353 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
(1232/34/36/38, 1298, and 1310). Any CANopen-compatible master can be programmed to control
the 1353.
The 1353 receives two PDOs and responds with two PDOs. These PDOs are fixed, simplifying the
VCL interface to the controller. 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 1353
to know that the system is still under master control. The 1353 also produces Heartbeat and Error
messages, which is the CiA-preferred safety and security method.

MINIMUM STATE MACHINE

The 1353 will run the CANopen minimum state machine as defined by CiA. The CANopen minimum
state machine has four defined states: Initialization, Pre-Operational, Operational, and Stopped.
When the 1353 powers up, it goes to the Initialization state; this is also known as the Boot-up state.
No CAN communications from the 1353 are transmitted in this state although the 1353 listens to the
CANbus. When the 1353 has completed its startup and self-tests, it issues an initialization heartbeat
message and automatically goes to the Pre-Operational state.
In the Pre-Operational state, the 1353 can receive and respond to SDOs and NMT commands, and
will send its heartbeat. It will not receive or send PDOs. When the master issues a goto Operational
State NMT command, the 1353 will go to full normal operation.
In the Operational state, the 1353 will start receiving and responding to PDOs and process all other
necessary CANopen messages.
3 — CANOPEN COMMUNICATIONS
Curtis 1353 CANopen Expansion Module Manual – June 2017
3 — CANOPEN COMMUNICATIONS
Power-On
Reset
Initialization
Transmit Boot-up
Pre-Operational
Operational
Reset
Module
Reset
Communication
Stopped
pg. 15