Reversible actuator control
The external hardware device consists of two on-board relays with volt free contacts that switch to provide power to either the open or the close command of the actuator. The component activates either relay for a proportion of the full scale drive time of the actuator (drive time is pre-defined by the manufacturer).
Figure 14. RaiseLower component
The acceptable input to this device is 0 to 10 volts, with staged control at 0v, 4v, 7v and 10v as detailed below:
| Volts | Raise | Lower | Function |
|---|---|---|---|
| 0 | Off | Off | Off |
| 4 | Off | On | Lower |
| 7 | Off | Off | Static |
| 10 | On | Off | Raise |
Figure 15. Example using the RaiseLower component
The wire sheet is an example of an actuator configured for a 100 second full-scale drive time. The initial actuator and virtual position values of are set at 0% (synchronized at fully lowered). Should the input signal increase to 40 percent, the raise output turns on for 40 percent of the full scale drive time (40 sec). A subsequent input decrease to 15 percent lowers the output to 25 percent of full scale drive time (25 sec) moving the actuator to 15 percent open.