Trigger Realignment by Networking Synchronized Embedded Hardware

摘要

This paper deals with the synchronization of the signals used to trigger measurement instruments (MIs) cooperating in the distributed measurement system (DMS). Whatever the synchronization protocol of the DMS nodes may be, the signal compatible with the trigger section of the MI is provided by specific software and hardware architecture. This architecture works as the trigger generator (TrG) and interfaces the DMS node. The problem is that the TrG degrades the synchronization accuracy among trigger signals in reference to the one guaranteed by the selected synchronization protocol. A solution based on the embedded synchronizing hardware (ESH) was formerly proposed as the middleware between the TrG and the MI to align the trigger signals. The continuous networking clock synchronization of the ESH ensures the submicrosecond accuracy throughout the measurement procedure. In this paper, attention is paid to the design criteria of the ESH in order to take into account the influence of the hardware components on the final synchronization accuracy and to find an effective strategy to reduce it. To this end, a mathematical model is pointed out to evaluate the contribution of each hardware component to the synchronization delay. Several results of experimental tests are shown to validate the proposed ESH in different operating conditions.