(1) Siemens dialog boxes have an option that says, “Do not display this message again.” This is handy for some annoying pop ups but it is really not a good idea to turn off important ones like warnings for overwriting blocks. These warnings are especially crucial if you are working on real machinery. If more then one person is using the software then you can reset these messages to display again by going to the SIMATIC Manager and select the menu Options | Customize. Click the General tab and press the Activate button. If it’s grayed out then all messages are set to display.
To try this out, I took a length of aluminium rod (actually just unscrewed the rod from a retort stand) and stuck LM335Z Temperature Sensor Linear ICs (Jaycar $) to the rod with some heatsink compound (Jaycar $) every 10 cm. These were held in place with wire twisties (zip ties would also work). One end of the rod was placed on a hotplate (150°C) and supported at the other end. I turned it on (about 150°C) and waited until temperature stabilised along the rod. I measured the output of each IC by connecting them in turn to an Arduino with a simple temperature reading 'sketch'. Download my sketch here if you like.