How to calculate and add CRC to all outgoing packets of with CCSDS_CHECKSUM

[shuq0]

I would like to use the crc_protocol.rb file to calculate and write the CCSDS_CHECKSUM of all outgoing packets. Is there a blog post showing how to append parameters to a defined cmd.txt file?

[dmccomas]

OpenSatKit (OSK), https://github.com/OpenSatKit/OpenSatKit, has an example of this. The INTERFACE definition in the cmd_tlm_server.txt specifies an interface ruby file. In OSK's case the following definition is made: cfs_interface = "INTERFACE LOCAL_CFS_INT udp_cs_interface.rb 127.0.0.1 1234 1235 nil nil 128 nil nil" OSK's udp_cs_interface.rb is located in cosmos/lib, https://github.com/OpenSatKit/OpenSatKit/blob/master/cosmos/lib/udp_cs_interface.rb and that defines a Write method that computes the checksum for a core Flight System (cFS) command packet. Checksums are part of the CCSDS secondary header which is user defined so the checksum algorithm in OSK is for the cFS.

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On Fri, Apr 8, 2022 at 4:22 PM shuq0 ***@***.***> wrote: I would like to use the crc_protocol.rb file to calculate and write the CCSDS_CHECKSUM of all outgoing packets. Is there a blog post showing how to append parameters to a defined cmd.txt file? — Reply to this email directly, view it on GitHub <#1529>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAMGKCAG7GRC4AA3O4INOHTVECIQDANCNFSM5S5RS7HQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[shuq0]

Follow up question. How do you set relative paths for custom interface files?

[ghost]

File are all relative to a plugin directory. So if your target is "INST" (like the demo"), you would use require "INST/lib/my_custom_interface.rb"