I'm a little late getting to the party on this one, but here we go.... As to "proportional", the MYPIN will not vary the voltage proportionally to a SSR. An SSR sees a triggering voltage, which can be within a certain wide range, and it then flips "on" like a mechanical relay, just with no moving parts. In essence it is a digital switch controlled by a DC triggering voltage. In your post quoted above you are using a 3 to 32v DC triggered SSR so any voltage between 3 and 32 volts DC will give the same result. The SSR triggers and the load on the output side is powered (the digital switch closes completing the power circuit). 3 volts does not give any different response than 32 volts so the value of the voltage is irrelevant as long as it is in the acceptable working range of 3 to 32v DC. A PID is a three mode controller. PID stands for proportional-integral-derivative, and the three values are normally working in concert with each other to perform the desired function. To just use a controller as proportional mode only unit defeats the whole purpose of using a PID. The output is generally either a static relay or a DC triggering voltage in 99% of the MYPIN's I've seen. There is a way to manually set the proportional value if an auto-tune fails, but again the output is a either a static relay or DC triggering voltage. If you are wanting a variable voltage output , it has to be a certain configuration MYPIN (output type code is "D"). Variable voltage will not work in concert with a SSR either. Variable voltage output MYPIN's are not that common, but they are out there. The most common will have SSR triggering output and/or static relay output. What model do you have? (should be on the sticker - post the full model number and a photo of the sticker would be best).