RTC
®
5 PC Interface Board
Rev. 1.9 e
15 Appendix A: The RTC
®
5 PC/104-Plus Board
585
innovators for industry
JP19: +5 V Power Supply
The RTC
®
5 PC/104-
Plus
board requires a +5 V power
supply. This isn’t available from all CPU boards on the
PCI bus, but is almost always available on the ISA bus
(if present). Therefore, the delivered RTC
®
5 PC/104-
Plus
board’s default configuration is for 5 V power
provided exclusively via the ISA bus (
JP19
open).
If a CPU board has no ISA bus, or if the ISA bus isn’t
connected to the CPU board, then Jumper
JP19
(on
the front side of the RTC
®
5 PC/104-
Plus
board, see
) can be rejumpered so that
power is supplied via the PCI bus, assuming that a
+5 V supply voltage is available there (be sure to
check your CPU board’s corresponding specifica-
tions).
JP10+12: 10 V Output Voltage for
ANALOG OUT1 and ANALOG OUT2
Jumpers
JP10+JP12
on the back side of the
RTC
®
5 PC/104-
Plus
) allow setting how the 10 V maximum
output voltage is generated at analog output ports
ANALOG OUT1 and ANALOG OUT2 on the LASER and
MULTI connectors:
PCI Local Bus Specification Revision 2.2 requires that
the PCI bus (pins A29 and A30) provide a ±12 V
supply. In reality, not all CPU boards supply this
voltage. Therefore, the RTC
®
5 PC/104-
Plus
board is
factory configured so that the 10 V maximum output
voltage is derived from the +5 V supply voltage
(provided either via the PCI bus or the ISA bus, see
) (
JP10
and
JP12
are both
set for position 2-3). In this configuration, the
maximum output current is +5 mA (source only).
If the CPU board actually provides ±12 volts (check
the corresponding specifications of your CPU board),
then rejumper as follows: both jumpers (
JP10
and
JP12
) in position 1-2. Then the maximum output
current is ±5 mA (source and sink).
JP19
+5 V power supply
open *
via the ISA bus
closed
via the PCI bus
(only if the ISA bus is
not
available)
Caution!
•
JP19
must
not
be closed if the RTC
®
5 PC/104-
Plus
board connects to the CPU board via both
the PCI and ISA busses and the CPU board
su5 V at both busses. Power provided at
both busses might damage the RTC
®
5 PC/104-
Plus
board.
* default configuration
Jumpers JP10+JP12
10 V Output Voltage
Position 1-2
derived from the ±12 V
supply of the PCI bus
Position 2-3*
derived from the +5 V
supply of the PCI/ISA bus
open
not provided
Caution!
• Ensure that
JP10
and
JP12
are not jumpered
differently (e.g. don’t set
JP10
for position 1-2
and
JP12
for position 2-3). Otherwise, the
board’s electronics will be damaged.
* default configuration
