765300 - Pyxis User Manual
Page 9
6. JUMPER SETTINGS
J4 3-pin landline modem power input select (1x3 pin header)
1
+5VDC
2
POWER In to LL Modem
3
+3.3VDC
Jumper across pins 1 and 2 for +5VDC commercial grade modem module.
Jumper across pins 2 and 3 for +3.3VDC industrial grade modem module.
CAUTION: Always check the Multitech modem modules data sheet prior to setting this
jumper as the wrong input voltage can damage the modem!
J6 6 pin base address selection (2x3 pin header)
A
B
C
Port
1
Port
2
Interrupt
Status
IN
IN
IN
3F8
2F8
220
*OUT
IN
IN
3E8
2E8
220
IN
OUT
IN
380
388
224
OUT
OUT
IN
240
248
224
IN
IN
OUT
100
108
240
OUT
IN
OUT
120
128
244
IN
OUT
OUT
140
148
248
OUT
OUT
OUT
160
168
24C
J8 22 pin Serial port 1 IRQ selection (2x11 pin header)
J9 22 pin Serial port 2 IRQ selection (2x11 pin header)
Allows IRQ selection for both serial ports. Set a 2mm jumper vertically on the desired IRQ as noted on
the silkscreen of the Pyxis board. If sharing the same IRQ for both serial ports only one of the ‘R’
jumpers needs to be installed. The ‘R’ jumper will add a 1K ohm resistor from the IRQ line to ground
which allows for tri-stated (inactive) IRQ’s to be held low. If both ‘R’ jumpers are installed and the IRQ
selected is the same for both serial ports then the resistors will be in parallel creating a 500 ohm
resistance and will load the IRQ line too much causing it not to function.
