Method of providing an allowable transmission time point for a reply in a question/answer communication between a supervisory module and a functional computer

Abstract

The invention relates to a method for providing a permissible sending time point for a reply in a question / answer communication between each monitoring module with a time base and a functional computer, the functional computer (120) sending at least one reply to the monitoring module (110), with The following steps: send a response setting the fault counter status (#FZ) to a value (W‑1) one increment ahead of a predetermined fault counter status threshold (W) when reached by The monitoring module outputs the fault signal (WDA), receives the fault signal (WDA), and determines the time interval (T) between the sending time point (ZSS) of the invalid response and the receiving time point (ZSWDA) of the fault signal (WDA). In the case of a defined time interval (T), a permissible sending time is provided for the reply by prescribing the sending time and / or the length of the response time delay (tRESP).

Description

technical field [0001] The invention relates to a method for providing permissible sending times for responses in question / answer communication between a monitoring module and a functional computer. Background technique [0002] Controllers, especially engine controllers, are usually monitored in a multi-level scheme. In particular, a question / answer communication is used between the monitoring module (UM) and the associated function computer (FR) in the monitoring concept of an EGAS system (eg engine controller) or in the transmission controller for the monitoring computer. In this case, the monitoring module checks whether the responses of the function computer are correct and whether they arrive at the correct time or within a defined time window. [0003] The disclosed monitoring system comprises at least one monitoring module and at least one functional computer to be monitored. For example, as disclosed in DE 102 05 809 A1, the computer and the monitoring module each...

AI Technical Summary

Problems solved by technology

However, providing a crystal oscillator in a functional computer produces a relatively high cost, so it is desired to provide a time base in a functional computer by a more cost-effective device, such as a PLL circuit.

However due to aging and manufacturing some PLL circuits have a much higher frequency error than quartz

The use of such circuits in existing systems is therefore not without difficulties, since the communication with conventional monitoring modules may be time-shifted, which can lead to impermissible response times outside the response window at certain times , and initiates an error response

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