Wieland samos PRO COMPACT - Node Guarding

CANopen gateway
Wieland Electric GmbH | BA000970 | 11/2016 (Rev. F)
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Node guarding
910839691
An NMT master (e.g. a PLC with integrated CANopen master) uses the NMT-Error-Control ob-
ject to detect a failure of an NMT slave with the
address N. The NMT slave must respond to the query of the NMT master within the node gua-
rding time. The node guarding time must be monitored by the NMT master.
The NMT master sends a CAN message with the identifier <700h + node ID> and RTRBit (re-
mote transmission request).
Query of NMT master:
Table 90: Query of NMT master
CAN-ID
RTR
DLC
DATA
700h + N
1
0
The slave (e.g. the SP-CANopen module) then sends a state byte 1 with the following content:
Response of the slave:
Table 91: Response of the slave
CAN-ID
DLC
DATA
700h + N
1
Byte1
Table 92: Remote transmission request
Bit
Meaning
7
Toggle bit changes its value between two consecutive queries
6…0 NMT status 4 = Stopped
5 = Operational
127 = Pre-operational
Bootup
On booting, the gateway sends a bootup message with the CAN-ID 700h+N, DLC = 1 and byte
1 = 0.
Heartbeat producer
When the gateway has been configured as a heartbeat producer (i.e. when SDO 1017 contains
a value for the producer heartbeat time, see table
"Supported SDOs" [ch. 10.10, p. 149] ), then
sends a cyclical message with the CAN-ID 700h+N, DLC = 1 and Byte 1 = 05h. The toggle bit
(bit 7) is always 0.
Heartbeat consumer
When the gateway has been configured as a heartbeat consumer (i.e. when SDO 1016.1 con-
tains a value for the consumer heartbeat time, see table
"Supported SDOs" [ch. 10.10, p. 149] ),
then at least one node guarding message must be received within the configured consumer
heartbeat time (typically from a NMT master).
10.7