18. SERIAL PROTOCOL SELECTION

Gemini has multiprotocol support on all 4 serial ports. Serial port protocols supported are RS232, RS422 and RS485.

The below table shows the mode settings of SP336 for protocol selection:

Mode 0	Mode 1	Mode 2	Protocol
0	0	1	RS232
1	0	0	RS485
1	0	1	RS422

Mode 0 of SP336 is always connected to Ground.

The serial protocols can either be selected by jumper setting or using software-programmable MPIO pins.

Click here for Jumper options for Serial protocol selection.

The below table shows the MPIO mappings from U2 IC to the Mode pins of SP336.

U2 Pin number	SP336 IC	Mode pin
C1	U4	Mode 0
D2	U4	Mode 2
D1	U5	Mode 0
E3	U5	Mode 2