Thank you for your replayIt's impossible to help given the limited information you've shared. How is the CRC calculated? Does the device use hardware handshaking signals? What are you using to communicate to it PC software? What communication settings (baud rate, data bits, parity, stop bits) are you using?
Can you provide a link or PDF of the manual for this controller?
If I send 0x55 0x55 0x01 0xD0 0x01 0x00 0xD0 it’s no responseOK, so you are able to get a successful response from device when sending 0x55 0x55 0x01 0xD0 0x01 0x00 0xF0. What do each of the bytes mean in this packet? It doesn't seem to use the same CRC, as calculating the CRC on 0x55 0x55 0x01 0xD0 0x01 gives 0x00D0, not 0x00F0. Does the device respond if you send 0x55 0x55 0x01 0xD0 0x01 0x00 0xD0? Perhaps it ignores the CRC.
Are you sure the users manual you're referencing actually applies to the device you have? Could there be another manual available based on the model number and/or firmware version installed on your device?
What is the other document that you reference here that has the 0x55 0x55 0x01 0xD0 0x01 0x00 0xF0 packet that works with your equipment?I use this package0x55 0x55 0x01 0xD0 0x01 0x00 0xF0 I got response back. This package didn’t show on documents but I got from another one