How to implement a custom CRC check function in StreamDevice?

[LONG FENG via Tech-talk <tech-talk@aps.anl.gov>]

Hi all,

StreamDevice provides some common CRC check methods, such as %<crc16>. However, sometimes we encounter non-standard CRC checks, like the CRC check of the SQM160, as shown in the figure .

In this case, we need to write a function to implement a custom CRC check and include this custom CRC function in the .proto file. 

How can we implement this process?  

Feng