Cameron NUFLO 1141C, User Manual

Page: 33 / 120

Chapter 3: Main Circuit Board Wiring
33
Figure 3.4— CN20 and CN21 connectors
Backup Batt (CN20) Jumper CN20 (Figure 3.4) enables and disables the lithium backup battery
power to the NVRAM. The Scanner 1141 is shipped with the battery
jumper in the OFF position. Set the jumper to ON before configuring the
flow computer and leave the jumper in the ON position when the Scanner
1141 is in operation. Loss of input power while the jumper is OFF will
scramble the entire contents of the NVRAM (including all configuration
and flow data), and a “superboot” will be necessary.
Note: Storage of the Scanner with the lithium battery jumper (CN20) in the ON position will drain
the lithium battery; if the lithium battery is drained, it must be replaced. If the computer is
stored without power for extended periods (i.e. a week or more), set the jumper CN20 to OFF.
Serial Port A02 (SW6) Serial port A02 (shown in Figure 3.5) is one of two auxiliary serial ports
(see also Serial Port A21) that can be software-configured to support either
RS-485 or RS-232C communications, depending on which hardware
options are installed. (Refer to the ScanWin manual,
Chapter 7: About the
System ).
For RS-485 communications, Resource A02 uses SW6 with terminals 14
and 15; if these terminals are not present, the RS-485 option is not
installed.
Switch 1 termination enabled when switch is closed. Termination can be
used if this is the last device in the RS485 loop, With low baud rates of
19200 bps the termination is not normally required.
Switch 2 pullup resistor enabled when switch is closed. Used with switch
3.
Switch 3 pulldown resistor enabled when switch is closed. Used with
switch 2.