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12. JUMPER DESCRIPTION

Describes Jumper block functionalities
The following figure represents the jumpers on Gemini and their default configurations. Default jumper configuration is highlighted in black.
Jumper Locations
Contact DSC for rugged options

12.1 JP1 Serial Termination Jumper

Gemini provides option termination resistors for RS422 and RS485 protocols.
When loaded a 121-Ohm resistor is connected across differential pairs. JP1 jumpers are not loaded by default.
The label number corresponds to silkscreen labels on PCB for pin locations.
Label
Jumper Pins
Function
1
1-2
121 Ohm Termination for Serial Port 1 TX
2
3-4
121 Ohm Termination for Serial Port 2 TX
3
5-6
121 Ohm Termination for Serial Port 1 RX
4
7-8
121 Ohm Termination for Serial Port 2 RX
5
9-10
121 Ohm Termination for Serial Port 3 TX
6
11-12
121 Ohm Termination for Serial Port 4 TX
7
13-14
121 Ohm Termination for Serial Port 3 RX
8
15-16
121 Ohm Termination for Serial Port 4 RX

12.2 JP2 Peripheral voltage selector

On Gemini, JP2 provides an option to select PCI I/O voltage level, LCD supply voltage, and LCD backlight supply voltage. The pinout is designed to prevent the possibility of shorting two supply voltages if loaded correctly.
The table below shows jumper settings for JP2. The default setting is highlighted in Bold.
Label Position
Voltage Selection
1-2 Left
V-PCI = 5V
2(across)
V-PCI = 3.3V
3(across)
V-LVDS = 3.3V
3-4 Left
V-LVDS = 5V
5-6 Right
V-Backlight = 12V
6(across)
V-Backlight = 5V

12.3 JP3 Serial Port Protocol Selector and USB Mux selection

Gemini has jumper JP3 to select the Serial protocols for serial port pairs and USB 2.0 signals for USB to I2C bridge or mini-card socket.
The serial port labels and associated functions are specified in the table below.
Jumper labels 2 and 3 must be used for serial protocol selection of Ports 1 and 2. Jumper labels 4 and 5 must be used for serial protocol selection of Ports 3 and 4.
Label 2/4 Jumper IN/OUT (Mode 2)
Label 3/5 Jumper IN/OUT (Mode 0)
Protocol
OUT
IN
RS232
IN
IN
Loopback
OUT
OUT
RS422
IN
OUT
RS485
USB 2.0 jumper option is as given below(default option in Bold):
Label
Function
Label 1 Jumper IN/OUT
USB 2.0 Assignment
IN
GPIO Expander
OUT
PCIe MiniCard