So am I correct to assume that the TMC222 is not programmable, but takes commands and response to them?
Let me give you some background
I have placed an order for two PD-108-28 and have been working with TMCM110.
PD-108-28 it uses the TMC222 and has a micro controller. That sends commands to the TMC222? So I am able program PD-108-28 using TCML. Correct? Therefore, I'm able to access the temperature flags in the program?
Yes, this is correct. The PD-108 uses a TMC222 and a microcontroller (which will be accessible via TMCL).
The TMC222 itself is pure hardware, it is not programmable (except some parameters like the address of the two wire interface that can be programmed into OTP memory).
I do not know of any PD-108 that were not shipped with TMCL. We will put the latest TMCL firmware and the latest TMCL-IDE on the web today. Please download both and try to do a firmware update then (using the TMCL-IDE and a properly working RS485 interface (best for this purpose is our USB-2-RS485)).
Yes, it would be best to do it with USB-2-RS485 (especially firmware dowloading)´.
When using other RS485 interfaces it might be necessary to set the "telegram puase time" to a value greater than 0 (try 20ms first and if this works you can go back in small steps). Please see the other threads about RS485 communication with TMCL.