Analysis - General
I am running a 100ms transient analysis on my schematic. The simulation gets to approximately the 30ms mark, and it then starts the simulation over again. It will then run through the entire simulation and any subsequent simulations. If I revert my circuit, I get the restart again during the first run. Why does the restart occur?
In the Preferences dialog box, there is an option called Convergence Assist which will be enabled. Convergence Assist is invoked if the simulation runs into convergence problems. It may modify Global Settings parameters such as RELTOL, ABSTOL, VNTOL, ITL2, ITL4, METHOD, GMIN, and others to achieve convergence. Since a change in the Global Settings can affect the SPICE matrix, the simulation needs to be restarted. If the assist succeeds, it adds a .OPTIONS statement to the text area of the circuit with the modified parameters so that subsequent runs converge more readily.