Timing and outage budget
These clauses hold the wireless system to one number: the worst-case outage left after the wired path takes its share of the tightest connection timeout the machine builder sets.
These clauses turn the application's timeouts into a binding number for the wireless network. They never set a timeout or a safety reaction time; those come from the machine builder's risk assessment and the applicable standards. The wireless system is held to the outage budget derived from them, worst case, not average.
Your values
Type your values, or work them out in the requirements translator. Blanks you leave empty stay marked in the text.
1.1 Design to the outage budget shall
The wireless system shall be designed so that no gap in valid packets it causes, whether from a roam, a scan, a rekey, a channel change, or retries, exceeds [Outage budget] ms on any connection carried by [Vehicle or machine]. This outage budget is the tightest connection timeout on the link, [Tightest connection timeout] ms, as configured by the machine builder, less [Allowance for the wired path and endpoints] ms allowed for the wired path and the endpoints.
1.2 Timeouts are fixed inputs from the project shall
The outage budget shall be derived from the timeouts configured in the controller, vehicle, and fleet manager projects, such as CIP Safety connection reaction time limits, EtherNet/IP connection timeouts, PROFINET watchdog times, PROFIsafe F-monitoring times, and fleet heartbeats, and not from protocol defaults. The wireless design shall take these timeouts as fixed inputs; any proposal to raise one goes to the machine builder and is outside the wireless scope.
1.3 Measure the wired allowance shall
The share of the timeout spent outside the radio, [Allowance for the wired path and endpoints] ms, shall be measured on the installed system, for example from the maximum observed network delay a CIP Safety controller reports, and shall not be assumed.
1.4 Report the worst case, not the average shall
Every timing figure the wireless vendor submits, including roam time, latency, and gap duration, shall be stated as the maximum observed over the test, with the number of samples, and not as a mean or median alone.
1.5 State the distance traveled during the budget should
For each vehicle, the design report should state the distance [Vehicle or machine] travels at [Vehicle speed] [Speed unit] during the outage budget, as a planning figure for the machine builder's risk assessment, without judging whether that distance is acceptable.
About this page
Built from 10 sources: 2 standards bodies and labs, 1 protocol owner or alliance, 1 research paper or thesis and 6 vendor documents. Researched and drafted with AI assistance, then reviewed and approved by Ben Rutter on . How pages are made
- First published
- Last updated
Change history (1)
- First published
Cite this page
Plain
Ben Rutter. "Timing and outage budget." OT Wireless, published October 6, 2026, updated October 5, 2026. https://otwireless.com/clauses/timing-and-outage-budget/
APA 7
Rutter, B. (2026, October 6). Timing and outage budget. OT Wireless. https://otwireless.com/clauses/timing-and-outage-budget/
BibTeX
@misc{rutter2026timingandoutagebudget,
author = {Rutter, Ben},
title = {{Timing and outage budget}},
year = {2026},
howpublished = {\url{https://otwireless.com/clauses/timing-and-outage-budget/}},
organization = {OT Wireless},
}