Emergency Messages; Heartbeat - Curtis 1356 Manual

Curtis 1356/1356P CAN Expansion Module Manual,

EMERGENCY MESSAGES

Emergency messages are the second highest priority in CANopen and the
highest priority that a slave (like the 1356 /1356P) can transmit. To minimize
the number of times Emergency messages can be set, a minimum time between
messages can be programmed using a Curtis programmer or an SDO.
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 all faults are clear.
Data bytes 4 through 8 define the specific fault. The 1356 /1356P will
place the current 24-bit hour meter into data bytes 4 through 6.
Bytes 7 and 8 are not used by the 1356 /1356P and are always 0x0000.
The emergency message format indicating an error is shown below.
byte 1
Curtis
Code
Error Code

HEARTBEAT

The Heartbeat message is a very low priority message, periodically sent by each
slave device on the bus. The Heartbeat message requires no response. Once the
1356 /1356P is in the Pre-Operational state, the Heartbeat message will be
issued continually 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.
Rev. A
3 — CANopen COMMUNICATIONS
0xFF 0x01 16-bit field
Hour Meter
byte 8
0x00
19