UMDIO128CO V2.0.1 Preliminary Documentation – May be Subject to Change 7-53
1.3.
Error Detection and Reaction
As shown in the last columns of Table 1, there are three types of errors that the DIO128 can detect
and react to:
1 = CAN Bus Error
Unit automatically enters BUSOFF state and stays there until reconnection
to the network is established
2 = Lost Heartbeat
When object
1016h, Consumer Heartbeat Time
sub-index 1, has a non-
zero valid entry. (Note: only one HB consumer is supported in this module)
3 = Lost RPDO1
When object
1400h, Receive PDO1 Parameter
sub-index 5 is written with
a non-zero value, the unit will expect to receive the message within that
timeframe (ms resolution) or else the unit will flag a lost RPDO1 error.
If any of these errors should occur, object
1001h, Error Register
will be set to 0x01 (generic error)
and the error will be added to
1003h, Pre-Defined Error Field
as outlined in Section 3.2.3.
In the case of a CAN network fault, the module will remain in the BUSOFF mode until the problem
is resolved, regardless of what is set in object
1029h, Error Behaviour
sub-index 1. Only once
the conditions causing the error are gone and connection to the network has been successfully re-
established will the unit evaluate 1029h.
If object
1017h, Producer Heartbeat Time
(default 0) is zero, the unit will send a heartbeat
showing that it is in BUSOFF mode (255) every 3 seconds in order to determine when the network
is present even if no other nodes are transmitting data at the time. If a heartbeat would be sent
regularly due to a non-zero value in 1017h, this feature is not required.
For a lost heartbeat or RPDO1, however, the unit will immediately evaluate object 1029h sub-
indexes 2 and 3 respectively, and change the node state accordingly. Both of these errors will also
set object 1001h to 0x01.
Only once all errors in the module have been cleared will object 1001h be reset to 0x00.
