Canopen Communications; Minimum State Machine - Curtis 1352 Manual

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Curtis 1352 eXm Manual,

CANopen COMMUNICATIONS

The eXm 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 (1234/36/38, 1298, and 1310).
Any CANopen-compatible master can be programmed to control the eXm.
The eXm's PDOs are fixed (see section 4). There is one incoming PDO-
RX (MOSI) for the driver commands and one response PDO-TX (MISO) for
the input status. Expedited SDOs (see section 5) are used to access all eXm
parameters and allow monitoring of non-runtime variables and flags.
The time between incoming PDOs is monitored and if excessive, will
flag a fault. This allows the eXm to know that the system is still under master
control. The eXm will also produce a cyclic heartbeat message, which is the
CiA-preferred method of slave node error control.
Emergency messages are sent sporadically whenever an error status flag
within the eXm changes state.

MINIMUM STATE MACHINE

The eXm 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.
Power-On
Initialization
Transmit
Pre-Operational
Operational
When the eXm powers up, it goes to the Initialization state; this is also
known as the Boot-up state. No CAN communications from the eXm are
transmitted in this state although the eXm listens to the CAN bus. When the
eXm 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 eXm can receive and respond to SDOs
and NMT commands, and will send its heartbeat. It will not receive or send
Rev. D
Reset
Communication
Boot-up
3 — CANopen COMMUNICATIONS
Reset
Module
Reset
Stopped
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