[TRNSYS-users] Equation : variable use / iteration

[Alex Rachid <wow134@hotmail.com>]

Dear All
 
I am writing an equation in TRNSYS:
 
1- For the next iteration I want to use the previous value of the same Variable
   
    example:
     T_COOL_ON = T_COOL_ON + PPD20 -PPDHI
      this is throwing an error.
 
2- How can I set the initial value of the variable (T_CCOL_ON in the previous example)?
     Should it be set in the "Simulation Cards"?
 
Regards & Thanks
 
Alex