9403 to control a relay (on/off heating)

Hello,

I am building a temperature control system, I already have the PT100 measurement using the module 9205 (16bit analog input). For the controlling of the temperature:

I am using 300W heaters connected to 230V and the 9403 module , as well as SSR Crydom ED24D3R. I am trying to do this "phase fired controller" in Labview. But I do not know how to get it arranged so that the PWM starts together with the AC .

Am I right with this reasoning? I don´t have much experience in this.

Any other ideas how to control the temperature with the heater-relay set-up?

Thank you! :)