Either the PortSet() or the WriteIO() instruction can be used to open and close the 7321 relay. These instructions are commonly used in conjunction with an IfThen/EndIf construction.
In this first example, the program closes the relay at the top of a 60 second interval and then opens the relay after ten seconds:
BeginProg
Scan (1,Sec,0,0)
If IfTime (0,60,Sec) Then
PortSet(1,1)
ElseIf IfTime (10,60,Sec) Then
PortSet(1,0)
EndIf
NextScan
EndProg
In this second example, the WriteIO() instruction is used to close the 7321 relay based on the measured panel temperature:
Public PTemp
BeginProg
Scan (1,Sec,0,0)
PanelTemp (PTemp,_60Hz)
If PTemp > 25 Then
WriteIO (&B00000001,&B00000001)
Else
WriteIO (&B00000001,&B00000000)
EndIf
NextScan
EndProg