
CANopen Firmware for PCAN-MicroMod
milliseconds. CANopen nodes may have zero, one, or multiple
Heartbeat Consumers [1016h,xxh] that can be configured to monitor
heartbeats from other nodes. If a node looses a heartbeat
monitored, it typically transmits an emergency message and goes
back into the Pre-Operational NMT state.
Inhibit Time
For TPDOs that implement a COS detection, the Inhibit Time is used
to prevent back-to-back transmission of input data that changes
frequently. The Inhibit Time is selected in multiples of 100s of
microseconds and specifies how long a CANopen node must wait
before it may transmit a TPDO again. Note that many CANopen
implementations do not offer such a high resolution and the Inhibit
Time might get rounded up to milliseconds.
Index
An Object Dictionary entry is selected using a 16-bit Index and an 8-
bit Subindex.
Layer Setting Services (LSS)
A CANopen standard defining how layer services like bit rate and
Node ID can be changed during operation.
Manager / Master
In CANopen there are several Master and Manager services,
typically combined into the ‘CANopen Manager’.
Message Identifier
Any communication technology used for CANopen (default is CAN –
Controller Area Network) must be able to assign a Message
Identifier to any message transferred. CAN uses the default of an
11-bit Message Identifier. The Default Connection Set selects how
these Message Identifiers are used.
Network Management (NMT)
Each CANopen node internally implements an NMT Slave state
machine with the major states being Pre-Operational (used to
configure devices), Operational (actively producing and consuming
PDOs) and Stopped (limiting communication to Heartbeats). The
NMT Master Message is used to command nodes to switch their
NMT States.
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