Simulation¶
Simulation rules update memory periodically. Use them to emulate changing process values without writing a custom Modbus device.

Rule Fields¶
A simulation rule can be added from the grid context menu or with Enter while the Simulation grid is focused. Double-click a row, or choose Edit simulation rule, to open the editor.

A simulation rule defines:
- memory area;
- start address;
- number of values;
- signal mode;
- period;
- minimum and maximum values;
- step value for counters.
Modes¶
- Counter increments values over time and wraps back to the minimum.
- Toggle alternates between
0and1. - Sine generates a smooth changing value between minimum and maximum.
- Random generates values within the configured range.
- Disabled keeps the rule configured but inactive.
Running Simulation¶
Simulation is controlled per server. Rules can be enabled or disabled individually.
Simulation writes are local writes. They update memory without marking client access indicators.
Use the row context menu to reset selected or all hit counters when you want a clean run without deleting the rule.
Practical Uses¶
Use simulation rules to:
- test trend displays;
- validate alarm thresholds;
- emulate counters and status bits;
- run repeatable demos;
- stress client polling behavior.
Table Controls¶
Simulation uses the shared table interactions for selection, shortcuts, column layout, row context menus, and the header context menu.
See Table Controls for the common grid controls.