Originally Posted by Boerderij_Kabouter
To program the controller to work properly with heating and cooling as we have discussed above... follow the same programming steps (now that the beeping has stopped ) to enter parameters "r0"=dep, "r2"=1.5, "c1"=dir, "c2"=inv, and "SP2"=-1.5.
Your programming is now complete and your controller ready to use. To exit the programming screen press set and the down arrow simultaneously.
To set your controller to your desired temperature, press "set" once. "SP1" temperature will flash. Use the arrows to select your desired temperature. Press "set". "SP2" temperature will flash, press "set" again to operate controller at your desired temperature.
"SP2" = -1.5 allows the controller to bring the chamber to temperature without over/under shoot. The temperature will glide to the set point.
I just received a new TSS2-2100. I was reading through the instructions and it seems that there is an "r3" parameter that effects two stage control (i.e. heating and cooling). Is this a new feature, or does your R2=1.5 and SP2=-1.5 setup do the same thing?
Here's what the instructions say:
"Neutral Area Mode (nEU)
Temperature of probe 1 >= SP1+r3 -->relay 2 ON
Temperature of probe 1 <= SP1 -->relay 2 OFF
Temperature of probe 1 <= SP1-r3 -->relay 2 ON
Temperature of probe 1 >= SP1 -->relay 2 OFF"
(For reference see page 4: http://www.dwyer-inst.com/PDF_files/TSS2_iom.pdf
I did some thinking and I think I understand now. The reason that the Neutral Area Mode won't work is that it doesn't allow you to correct for thermal mass of the system. With heating (in a water bath, say), you would always overshoot your temps because it won't turn off the heater until it hits SP1.
I thought it might be possible to set r3 negative (say r3=-1.5), but this would just make the heating and cooling turn on at the same time and fight each other. It is potentially great for very precise temperature control, but you'll waste a ton of energy.
I also think I understand your setup now, but I have one remaining question: why do you set SP2 and R2 to 1.5 degrees and not a smaller value (0.5 degrees, say)? By my calcs, if your desired set temp is 68, for example, your settings would let the set temp vary between 65 and 69 degrees (SP1+SP2-r2 and SP1+r1, respectively). I understand that you want to stop heating early to account for thermal mass, but this could be controlled by either SP2 or r2 individually. Here's a possible alternate setup:
SP2=-1.5 (to account for thermal mass)
This should hold temps between 66 and 68.5F. (Disclaimer: I haven't actually set up my temp control system, so this is all theoretical until I get the darn thing assembled and tested.)
(Also note that the diagrams and instructions in the above link are incorrect, but it's pretty clear what the instructions should say. These clearly weren't edited by anyone. Maybe I'm the only person to have ever read them...)