Description of ASCII and Binary Logs with Short Headers
One difference from the standard OEM7 logs is there are two possible headers for the ASCII and binary versions of the INS logs. Which header is used for a given log is described in the log definitions in the SPAN Logs chapter. The reason for the alternate short headers is that the normal OEM7 binary header is quite long at 28 bytes. This is nearly as long as the data portion of many of the INS logs and creates excess storage and baud rate requirements.
These logs are set up in the same way as normal ASCII or binary logs except a normal ASCII or binary header is replaced with a short header (see Table: Short ASCII Message Header Structure and Table: Short Binary Message Header Structure).