Rivendell Interprocess Communication Protocol This defines the IP protocol used for communication between different modules of Rivendell and the 'ripcd' daemon. Connection to ripcd is by means of a TCP SOCK_STREAM connection to TCP port 5006. The format of a message is as follows: [][...]! where: is a two-letter code indicating the nature of the message. is zero or more arguments. ! is an ASCII character 0x21. UNPRIVILEDGED COMMANDS -- no authentication is required to execute these. DC! -- DROP CONNECTION End the session and drop the TCP connection. PW ! -- SEND PASSWORD Send a password to authenticate the connection. Ripcd will respond with 'PW +!' or 'PW -!', indicating the success or failure of the authentication. PRIVILEDGED - a connection must be authenticated before these can be executed. RU! -- Request User Request the LOGIN_NAME of the user currently logged in. Ripcd will respond with RU !. SU ! -- SET USER Log in. Ripcd will respond with RU ! MS ! Send an RML command to the specified destination. ME ! Send an RML echo to the specified destination. GC ! Return the current GPI line cart numbers for matrix . Return for each line: GC ! Indicates a change in a GPI line cart number (receive only). GD ! Return the current GPO line cart numbers for matrix . Return for each line: GD ! Indicates a change in a GPO line cart number (receive only). GI ! Return the current GPI line states for matrix . Return for each line: GI ! Indicates a change in a GPI line status (receive only). GO ! Return the current GPO line states for matrix . Return for each line: GO ! Indicates a change in a GPO line status (receive only). GM ! Return the current GPI line mask states for matrix . Return for each line: GM ! Indicates a change in a GPI line mask status (receive only). GN ! Return the current GPO line mask states for matrix . Return for each line: GN ! Indicates a change in a GPO line mask status (receive only). RG! Reload the GPI table. TA! Request the current state of the On Air flag. Ripcd will respond with TA 0|1!, with 0 = Off and 1 = On.