FOLSOM ScreenPRO FC-0608 Installation And Operator's Manual page 53

If a command is recognized as valid but the parameter list is somehow incorrect, an "!ERR_#<CR><LF>" is returned
to indicate an error. The # will have a numeric value that specifies the type of error. After this line is sent out the
prompt will be returned to indicate the system is ready for a new command.
Error Codes
1 - Insufficient number of arguments supplied.
2 - At least one of the arguments is invalid (out-of-range value).
3 - Checkum error, specific to the PASS command only.
4 - No reply from BlendPro, specific to the BPQUERY command only.
5 - Requested preset doesn't exist.
Manual #26-0111200-00 / Revision E ScreenPro Multi-Screen Remote 49