Variables
In the formulas, different variables are available to access controller inputs or outputs or other statuses of the simulation.
Table: Variables available to access controller inputs and outputs
| I1 I2 … I16 | Current value of a controller input Value of the controller input in the current time step of the simulation. Only variables that are linked to sensors are allowed for use. |
| PI1 PI2 … PI16 | Latest value of a controller input Value of the controller input from the latest time step of the simulation. Only variables that are linked to sensors are allowed for use. |
| O1 O2 … O16 | Current value of a controller output Value of the controller output in the current time step of the simulation. Only variables that are linked to actuators are allowed for use. |
| PO1 PO2 … PO16 | Latest value of a controller output Value of the controller output from the latest time step of the simulation. Only variables that are linked to actuators are allowed for use. |
| H1 H2 … H8 | Current value of an auxiliary variable (constant, formula or time delay) Value of the auxiliary variable in the current time step of the simulation. Only previously defined variables are allowed for use. |
| PH1 PH2 … PH8 | Latest value of an auxiliary variable (constant, formula or time delay) Value of the auxiliary variable from the latest time step of the simulation. Only previously defined variables are allowed for use. |
| S | Number of the active status (operating status) in the current time step of the simulation. The variable may include values ranging from 1 to the number of defined states (max. 16). |
| PS | Number of the active status (operating status) from the latest time step of the simulation. The variable may include values ranging from 1 to the number of defined statuses (max. 16). |
| TS | Current time step in seconds since the start of the simulation (January 1st 00:00) |
| PTS | Last time step in seconds since the start of the simulation (January 1st 00:00) |
| TC | Signal of the time switch from this controller. Returns the value 1 if the time switch is on, 0 if the time switch is off. |
| PI | Constant π |
All numbers included in the formulas should use the “point“ as a decimal separator (regardless of the “Language and Region” setting in Polysun). The symbol “E“ may be used as an exponent, for example 1234.6 or 1.2346E3
Controller inputs may be used for the following variables. For the variables from I1 to I16 or from PI1 to PI16, the value is returned in the following basic unit (regardless of the “Units” setting in Polysun):
Table: Basic units of measure for the variables from I1 to I16 or from Pl1 to Pl16
| Temperature | °C |
| Area | m2 |
| Power | W |
| Specific power | W/m2 |
| Thermal conductivity | W/K |
| Heat capacity | J/(l*K) |
| Flow-rate | l/h |
Controller outputs may be used for the following variables. For the variables from O1 to O16 or from PO1 to PO16, the value is returned in the following basic unit (regardless of the “Units” setting in Polysun):
Table: Basic units of measure for the variables from O1 to O16 or from PO1 to PO16
| Status | Without unit, on/off signal, value 0 or 1 |
| Percentage | Without unit, analogue control signal, value from 0 to 1 |
| Leistung | W |
| Flow-rate | l/h |