SimSync Engine

For OTS systems (not Checkout), run the SCP installer on Foxboro workstations running either FoxView or Foxboro Evo Control HMI. For Foxboro Evo Control HMI or Wonderware Historian, the Foxboro Evo Simulation software is also required. This additional software installs simulation components for the HMI and historian. One component is the SimSync Engine.

The SimSync Engine controls the time, trending, and alarms on the Foxboro workstations. The SimSync Engine freezes the trends when the simulation is frozen so that the trends do not "flat line." The SimSync Engine archives alarms in the snapshot. The SimSync Engine maintains constant trend ramp rates when the simulation speed is increased or decreased. It does this by adjusting the time displayed on the trend. If the simulation is run faster than real time (> 100%) the "current time" shown at the right side of the trend time span will advance faster than the wall clock time. If the simulation is run slower than real time (< 100%) the "current time" shown at the right side of the trend time span will advance slower than the wall clock time. This skewed simulation time can be confusing because the time shown on a trend or on an alarm may be in the future or in the past with respect to the computer system time.

The SimSync Engine is required on every SCP machine for precise speed control of SCP Apps and correct alarm timestamp when running faster/slower than real time. The SimSync Engine resolution setting controls the resolution of alarm timestamps. A large SimSync Engine resolution value (number of time slices per second) produces more alarm timestamp granularity than a small resolution value. The granularity increases the user’s ability to determine which alarm came in first when a large groups of alarms is generated but has the potential to limit the simulation maximum speed.

The SimSync Engine allows theDYNSIM Simulation Executive to control the simulation time-related functions associated with the HMI. These functions include:

• freeze and run the simulation

• save and restore the snapshots (tags, trends, alarms)

Simulation time control, through the DYNSIM Simulation Executive, includes freeze, run, fast and slow time as well as snapshot save and restore.

Important! Include a SimSync Engine on the SCP computer and on every Foxboro installed computer. This is required so that the time stamp of an alarm will match the time stamp of the associated trend.