Hi,
I could not find any information on the controller you are using, but is there is a manual mode, you may wanto to test it manually without any software interaction. This may help you determine the limits of the cotroller.
Another thing that you can do is have the program read the message returned when you set the temperature; some instruments check the range and if they detect that a setting is out of rage they will return an error message.
Before you go into software, you should make sure that the hardware and the setup that you have are capable of reaching that temperature.
I hope this helps.
Regards,
Juan Carlos
N.I.