Front panel IC-706

Cable pinout

Pin  	Signal 	Color         Description
1 	LRXD 	Yellow        Data transfer from front panel to the radio.
2 	LTXD 	Black         Data transfer from radio to the front panel.
3 	8V 	Blue          DC power (8V) to the front panel.
4 	AF 	Red           Output audio to headphone jacket.
5 	GND 	Shield        Data, power, output audio and power control ground.
6 	MIC 	White         Microphone input.
7 	MICE 	Green shield  Microphone ground.
8 	PWK 	White         Power control (switch ON button). Active in low.

Switch on

Power switch on panel turns PWK signal to low (ground). Radio turns on supply voltage on pin 8V.

Communication

Both sides communicate at 19200 Baud, 8 bits, no parity, 1 stop bit. Protocol is similar to CI-V control. AFAIK it is not published so next informations are taked by reverse-engineering.

• Packet starts with Preamble code (0xfe).
• Second byte is probably Command number.
• Third byte is probably Sub command number. Mostly 0x00.
• Folowing Data area with variable length.
• Last byte is End of message code (0xfd).

Commands

0x0b

Keepalive packet sent from panel to radio about every 100 ms. When no packet is received by radio in about 200 ms, it switches itself off. To provide reliable work over IP networks, this packet should be emulated.

0x60

Data to display on panel. Looks like bitmask controlling particular LCD segments/LEDs. No detailed description available at this time.