Garmin Apollo SL30 COMM Installation Manual

Also see for Apollo SL30: Quick reference guide Pilot's guide Pilot's guide Installation

Serial Interface Specifications60 Apollo SL30 Installation ManualD ATA FORMATThe data format for the serial communication is:• Baud rate 9600• Data bits 8• Stop bits 1• Parity noneD EFAULT MESSAGE O UTPUTAt system start when the SL30 is configured to operate in normal mode, the following messageswill be configured for output at the specified rates:• CDI, VDI, and Flags at 10Hz (high rate).• Decoded OBS Setting at 10Hz (high rate).• Radial from Active VOR at 10Hz (high rate).• Radial from Standby VOR at 1Hz (low rate).• Decoded Station Identifier at 1Hz (low rate).• NAV Receiver Status at 1Hz (low rate).• Comm Transceiver Status at 1Hz (low rate).These default rates can be changed by using the Request Data Output message.MESSAGE FORMATSAll messages will conform to the NMEA 0183 proprietary message format as follows. Allcharacters will be standard ASCII characters. No binary data characters will be used.“$” ............................Start of message character, ASCII “$” (024h).“P” .............................Proprietary message identifier.“MRR” ......................II Morrow company identifier.c..................................Message class identifier. Used to identify a message as either aCOMM or a VHF NAV message. Those message types which arealso supported by the SL40 VHF Comm Radio Serial Interfacewill use the “C” identifier to allow the SL30 to accept COMMradio commands from existing products. All other messages willuse the “V” identifier to indicate that they relate to a VHF NAVreceiver.nn .............................Message identifier, two-digit number in ASCII characters.d.....d ........................Message data characters defined for each message.chksum .....................Message checksum, including message identifier through datacharacters. The two-digit checksum is generated by adding allvalues of valid characters together, ignoring carry (if any). Thisvalue is converted into two encoded hex1 characters (30h-3Fh).1 Encoded hex: each character consists of 4 bits of data placed in the low order nibble +30h. For example, the 8-bitvalue 5Fh would be encoded as two characters with values of 35h and 3Fh, which map to the ASCII characters “5”and “?”, respectively.