Emergency Messages; Heartbeat - Curtis 1353 User Manual

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EMERGENCY MESSAGES

Emergency messages are the second highest priority in CANopen and the highest priority that a
slave (like the 1353) can transmit. These messages are sent sporadically whenever there is a change
of state in the 1353's fault flags.
To prevent fast-changing fault bits from flooding the bus, a minimum Emergency Rate between
messages can be programmed by Curtis programmer or SDO.
An Emergency Message consists of 8 data bytes.
Data bytes 1 and 2 define the error category.
Data byte 3 is the CANopen-required error register. Curtis products define this as 0x01 if there is a
fault present and 0x00 when this fault is clear.
Data bytes 4 through 8 define the specific fault. The 1353 will place the current 24-bit hour meter
into data bytes 4 through 6.
Bytes 7 and 8 are not used by the 1353 and are always 0x0000.
The emergency message format indicating an error is shown below.

HEARTBEAT

The heartbeat message is a very low priority message, periodically sent by each slave device on the
bus. The heartbeat message has a single byte of data and requires no response. Once the 1353 is in
the Pre-Operational state, the next heartbeat will be issued and will continue until communication
is stopped.
The heartbeat message has only one data byte. The top bit is reserved and should be set to zero. The
bottom 7 bits hold the current NMT device state.
3 — CANOPEN COMMUNICATIONS
Curtis 1353 CANopen Expansion Module Manual – June 2017
byte 1
Curtis
0xFF 0x01 16-bit field 0x00
Code
Error Code Hour Meter
byte 8
0x0000
pg. 19