Active Model per Device

Choosing follow global removes that device's override, so it picks up the global model from the dashboard. Saving writes one path-keyed entry per device, which is what lets two units that share a file name — such as pcs1 and pcs2 — run different models at the same time.

Pull models from EMS reads the model each unit is set to in ems_control_setting.json and writes those as the active models here, so a model changed on the EMS reaches the simulator in one click. Devices the EMS does not describe keep the model they run now, and any unit whose EMS model has no variant file is reported rather than written. The dropdowns stay free for one-off changes either way. A simulator restart applies the result.

Run decides whether the simulator starts that device's Modbus server at all. Every server costs CPU, so switching off units you are not testing is the quickest way to take load off the host. A ticked device runs; untick one and it is skipped on the next start.

Run only EMS active devices fills those ticks in from ems_control_setting.json: a device runs only if the EMS describes a unit that uses it. That is how the simulator stops spending CPU on hardware the site does not have. Anything the EMS does not mention is switched off, and a device the EMS cannot be read for is left exactly as it is rather than being stopped on a failed read. Ticks stay editable afterwards for one-off runs, and both buttons need a simulator restart to take effect.