PROFINET IO
8.5
PROFINET IO communications and connection timeout
The PROFINET IO declares a watchdog time within which both master and slave must send IO back
to each other. This watchdog time is a factor of the communication cycle time and is set by the
master. Minimum cycle time for PROFINET IO is 1 millisecond.
In case of normal communication mode, 4 ms is the fastest recommended cycle time for PROFINET
IO. Faster cycle times (1 ms and 2 ms) are recommended in Fast Mode. See Chapter 16 "Appendix 6
- Fieldbus option board communication" for more details.
The PROFINET IO also declares the process data validity on a submodule level. This validity is
informed between provider and consumer with the IOPS (Input/Output Provider State) byte. If the
incoming data validity is other than GOOD, this data is completely ignored and last valid data is used.
When the data state toggles from GOOD to BAD or an IO message is not received within the
watchdog time, the timeout setting value is activated and a fault is created after it elapses. This
means that the panel parameter "Communication timeout" (refer to chapter 6.1.6) is used as an
additional timeout value. The same behaviour applies if a connection is closed or the cable
disconnects (link loss). See Figure 44 for the timeout fault logic.
Cable disconnected
Connection closed
Figure 44. PROFINET IO communication and timeout fault
The option board will set its data status to GOOD as soon as it receives valid data from the AC drive.
Unless the communication to the AC drive breaks, the data remains GOOD. The IOCS are GOOD as
soon as the option board is able to receive and handle IO data.
Local contacts: https://www.danfoss.com/en/contact-us/contacts-list/
Connection
established
Communicating
Check
Received packet within
watchdog time?
No
Communication
timeout zero?
No
Has additional
Yes
timeout elapsed?
Yes
FAULT!
Yes
Is received
Yes
IOPS GOOD?
No
Yes
Has IOPS been
GOOD?
vacon • 131
No
11719_uk
8
Need help?
Do you have a question about the optea and is the answer not in the manual?
Questions and answers