I wanna convert data of Error Code 1 Date Time H (0x6578) and Error Code 1 Date Time L (0x7AE) to timestamp from Modbus TCP Server, but the result I got was "5/16/1973 Wednesday 11:27:42", this is unlogical result, this alert was happened within this month and this facility was built in 2022.
Can someone tell me how to convert it to the correct Timestamp?
The "Time H" part likely describe the High 16 bit, while the "Time L" part describes the Low 16 bit. This makes the resulting timestamp 0x657807AE (decimal 1702365102), which when used as a UNIX timestamp (number of seconds since 1970/1/1) means Tue Dec 12 07:11:42 2023 UTC.
The error you did was to use 0x65787AE instead of 0x657807AE, i.e. ignoring that the lower bit 0x7AE is just a short way of writing 0x07AE (with 0) and only the latter shows all 16 bit.