RS232 Protocol
8
Section 2: Feedback String Format
Standard Response String Format
Start Count ID Type Data (xx Bytes)
0xFE 0x37 0x22 0x20 Flag1 … Flag4 tChar0 … tChar4
Data Checksum
Line1(0) … Line1(21) Line2(0) … Line2(21) 0xXX
The feedback string is a representation of the display of the unit. The Flag1 – Flag4 data
bytes contain data on which of the various icons on the front display are currently
illuminated. The tChar0 – tChar4 data bytes contain ASCII data representing the
numeric text that appears in the front right corner of the display. It can contain current
frequency information when the unit is tuned to an HD Radio station.
The Line1 – Line2 data bytes contain ASCII data representing the text that appears
across the front display. It can contain current frequency information, as well as RDS
radio text data and should be parsed to obtain this information. The RT-1084 uses a 2
line display, however depending upon the mode (FM, HD Radio, Sirius), the display can
sometimes be 1 line of text or 2. The Text Mode flag bits in Flag 4 will indicate what
mode the display is currently in.
The display status uses 1 bit in Flag4 to confirm if the front display is On or Off.
The Type 1/2 bits were added with Software V1.79. These bits are used to determine if
the current feedback data is for the HD Radio, Sirius 1, Sirius 2 or Sirius 3 modules.
Flag1 – Flag4 Data
Flag1 Flag2 Flag3 Flag4
Bit0 DAB Tuned MHz Text Mode 1
Bit1 RDS Stereo DP Text Mode 2
Bit2 Signal Bar 3 AF COL Type 2
Bit3 Signal Bar 2 PTY AM Type 1
Bit4 Signal Bar 1 Memory FM Display Mode
Bit5 Signal Bar 0 Auto HD Radio Standby LED
Bit6 Ant Preset Sirius kHz
Bit7
Display Status
Display On Display Off
Display Mode 0 1
Display Text Status
1 Line (13 Char) 1 Line (13 Char) 2 Lines (22 Char)
Text Mode 1 0 1 0
Text Mode 2 0 0 1
Feedback Type Status
HD Radio Sirius 1 Sirius 2 Sirius 3
Zone 1 0 0 1 1
Zone 2 0 1 0 1