3 Basics

IL•1F CANopen DS301

Connection error The NMT master signals a connection error to the master program if:

the slave does not respond within the "guard time" period

the NMT state of the slave has changed without a request by the NMT master.

Figure 3.32 shows an error message after the end of the third cycle be- cause of a missing response from an NMT slave.

 

request

 

Master

response

Slave

guard

 

life

time

request

time

 

 

 

response

 

 

request

 

 

no

 

 

response

 

message

 

 

Figure 3.32 "Node Guarding" and "Life Guarding" with time intervals

Boot-up message The communication profile DS 301, version 4.0, defines an additional task for the NMT services: sending a boot-up message.

A network device informs all other network devices that it is ready for op- eration using a boot-up message.

A boot-up message consists of the COB ID of the NMT object NMT Er- ror Control and is transmitted without data. The default setting of the COB ID is 1792 (700h) + node-Id

0198441113586, V2.01, 11.2008

50

Fieldbus interface

Page 50
Image 50
Schneider Electric DS301 manual Node Guarding and Life Guarding with time intervals