9. Jumpers and Connectors Overview
20
PCI-760 – User’s Manual (V1.00)
9.1.2.
Jumpers on the PCI-760
The jumpers on the PCI-760 allow you to configure your CPU card according to the needs of your applications.
In order to change a jumper setting, turn off the computer using the ATX-power supply switch.
If your power supply has no On/Off switch, disconnect the main power source. The board otherwise
could be damaged.
The following examples show the conventions used in this section.
2
1
Jumper Open
2
1
Jumper Closed
9.1.2.1.
JP1 and JP2: Jumpers for COM2 Configuration as RS422 or RS485
The serial port COM2 (RS232 default setting) can be configured in the BIOS setup RS422 or RS485.
The jumpers JP1 and JP2 allow you to connect or disconnect the termination resistors (120 ohm) on / from the serial port
COM2, when the operation mode in the BIOS is set to RS422 or RS485.
When installing the board at one end of the network, JP1 and JP2 jumper caps must be installed to
connect the 120 ohm termination resistors.
In RS422 mode, both jumper caps (JP1 and JP2) must be installed to connect the 120 ohm line
termination resistors.
JP1:-Pin Row, DIP 2-pin
Setting
Function COM2 (RS422)
2
1
Pin 1-2
Short/Closed
RS422 with connected termination resistor
2
1
Pin 1-2
Open (Default)
RS422 without connected termination resistor
JP2:-Pin Row, DIP 2-pin
Setting
Function COM2 (RS485 or RS422)
2
1
Pin 1-2
Short/Closed
RS485 or RS422 with connected termination resistor
2
1
Pin 1-2
Open (Default)
RS485 without connected termination resistor
The serial port COM2 (RS232 default setting) can be configured in the BIOS setup RS422 or RS485.
Refer to BIOS settings for COM2 configuration as RS422 and RS485.