Dear Rashid,

You have to make sure that the settings on the Desigo Insight management station are done correctly and hat the baud rate corresponds with the baud rate of the NCRE controller.

Please find attached the engineering manual with the necessary settings for the Desigo Insight NCRE connection. Please note that you have to install a direct link (0-modem) connection and to set the correct baud rate. 

Regarding your specific questions:
1. Yes, it should be possible to use USB – RS232 converters.  But this may depend on the converter used. Correct settings are essential.
2. You should be able to use both host ports A or B. Please note that dip switch  4 is not relevant for the host port. Please put S3 switch 5 to 0 and switch 6 to 1 for host A fixed to 9600 baud and put S3 switch 5 to 0 and switch 6 to 1 for host port B fixed to 9600 baud.
3. Please contact your local Siemens branch office or Siemens representative to get the manuals of the old INTEGRAL system.
4. We do not have specific diagnostic programs. Desigo  Insight has a build in diagnostic, the Trace Viewer.  Using this tools requires specific in-depth system and engineering knowledge.  

Please note that this is quite a complex topic  and it may be very difficult to get the system running without the detailed system information or a training. We therefore recommend to contact your local Siemens BT branch office or a Siemens representative to get support.

Best regards,
Albis