Update time (PROFINET)
In PROFINET, the configured interval at which an IO controller and an IO device exchange cyclic IO data, set per device.
The network analogy
The PROFINET counterpart of the EtherNet/IP RPI: a configured transmit interval for each stream, watched by a timer on the receiving side.
Why it matters for wireless
The connection is monitored with a multiple of the update time, so the update time decides how long a roam or interference burst can last before the IO device drops out. Faster updates also mean more frames per second competing for airtime.
PI’s system description says cyclic IO data travels unacknowledged, with update times chosen per device, and separately for inputs and outputs, within 250 µs to 512 ms1. The consumer watches the connection with a time setting derived from a multiple of the update time and reports an error to the application if data misses it.
These frames run directly on Layer 2 with Ethertype 0x8892, without TCP/IP. With no IP header, the wireless hop that carries them has to bridge at Layer 2. PI’s installation table lists WLAN and Bluetooth under Conformance Class A.
About this page
Built from 1 source: 1 protocol owner or alliance. Researched and drafted with AI assistance, then reviewed and approved by Ben Rutter on . How pages are made
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Cite this page
Plain
Ben Rutter. "Update time (PROFINET)." OT Wireless, published October 5, 2026. https://otwireless.com/glossary/update-time/
APA 7
Rutter, B. (2026, October 5). Update time (PROFINET). OT Wireless. https://otwireless.com/glossary/update-time/
BibTeX
@misc{rutter2026updatetime,
author = {Rutter, Ben},
title = {{Update time (PROFINET)}},
year = {2026},
howpublished = {\url{https://otwireless.com/glossary/update-time/}},
organization = {OT Wireless},
}