Lenze 931K - Manual (Page 53)

CANopen communication
Node guarding telegram
Telegram structure
5
l
53 KHB 13.0002−EN 4.1
5.9.2 Telegram structure
Remote Transmit Request (RTR)
1 8 . . . .
t s
RTR
Confirm Response
Request Indication
NMT-Master NMT-Slave
9400CAN020
The NMT master cyclically sends a data telegram to the NMT slave which is referred to as
remote frame (Remote Transmit Request/RTR).
ƒ For this purpose, the RTR bit in the arbitration field of the RTR is set to the valency
LOW (dominant level).
ƒ The RTR does not contain user data.
ƒ Identifier 700
h
+ adjustable node address
11 bits 1 bit User data (0 byte)
1st byte 2nd byte 3rd byte 4th byte 5th byte 6th byte 7th byte 8th byte
Identifier RTR bit
701 R 0
Response
After this, the NMT slave will send a response message ("response") with a user data width
of 1 byte. The identifier of the response message is the same as the identifier of the RTR
telegram.
11 bits 4 bits User data (1 byte)
1st byte 2nd byte 3rd byte 4th byte 5th byte 6th byte 7th byte 8th byte
Identifier
Data
length
Toggle
bit/NMT
status
701 1 T/N
The user data contain the NMT slave status (s, bits 0 ... 6) and the toggle bit (t, bit 7).
)
Note!
The toggle bit is monitored by the NMT master.
If a telegram is received with the incorrect value in the toggle bit, it is treated
as if it were not received; i.e. the monitoring time is not reset and elapses
further.
ƒ The toggle bit
– has the value "0" when the node guarding telegram is activated for the first time.
– must change its value with every response.
– can only be reset to "0" by the "Reset_Communication" telegram of the NMT
master.
ƒ The NMT slave can change to the following states: