Campbell Scientific SDS122 Two-Way Serial Data Switch - Manual (Page 12)

SDS-122 SERIAL DATA SWITCH
8
4.3 DEFAULT JUMPER SETTINGS
JUMPER DEFAULT DESCRIPTION
PL41 Not fitted When jumper PL41 is fitted, port A/B on the 3-way screw
terminal will output 0V for switch on port A, or 5V for switch on
port B when the SDS-122 is in AUTO mode only. When the
jumper is not fitted, or the unit is in MANUAL mode, then the line
becomes an input.
PL42 Not fitted When jumper PL42 is fitted the SDS-122 will default to the port
selected by PL43 when the ME line goes low. When the jumper
is not fitted, the unit will stay with the last port used after the ME
line goes low.
PL43 Not fitted This jumper works in combination with jumper PL42. When
jumper PL43 is fitted
and jumper PL42 is also fitted, the SDS-122
will revert to port B when the ME line goes low. When PL43 is not
fitted, but PL42 is fitted, the unit will default to port A when the
ME line goes low.
PL44 Not fitted When jumper PL44 is fitted and synchronous data is transmitted,
(e.g. to a storage module), the SDS-122 will block any data
output to port A. When PL44 is not fitted all data is allowed to
pass through to port A.
SW1-5 DCE Jumper block SW1-5 can be set so that port A can emulate
either a DCE or DTE interface, and so there is no requirement for
a null modem cable. The ‘DCE’ and ‘DTE’ jumper positions are
marked on the PCB. Note that, to change the settings, the whole
jumper block is removed and re-inserted at 180
°
. The red line on
the jumper block should be adjacent to the state (DCE or DTE)
required.
SW6-10 Isolated Jumper block 6-10 can be set so that port A is either optically
isolated or powered. RAD- SRM short haul modems would be
driven in the powered mode. ‘Isolated’ and ‘Powered’ positions
are marked on the PCB. Note that, to change the settings, the
whole jumper block is removed and re-inserted at 180
°
. The red
line on the jumper block should be adjacent to the state (Isolated
or Powered) required.
PL50 Fitted When jumper PL50 is fitted, not less than 4.3V is supplied to pins
20 and 4 of port A in DTE mode and to pins 5 and 6 of port A in
DCE mode. RAD-SRM modems in interactive communications
would need the PL50 jumper to be fitted. The actual voltage
supplied to the pins will depend on the setting of jumper PL51
(see below). When the jumper is not fitted, no voltage is
supplied. This has no effect in isolated mode.
PL51 Not fitted When jumper PL51 is fitted, >7V is permanently output to pins 20
and 4 of port A in DTE mode and to pins 5 and 6 of port A in
DCE mode. This jumper is not normally fitted for RAD-SRM
modems in interactive communication. When not fitted the
outputs are shut off when ME goes low.
PL56 Not fitted When jumper PL56 is fitted, >7V is supplied to the handshake
lines (pins 20 and 4 of port A in DTE mode and pins 5 and 6 of
port A in DCE mode) when either ME or SDE/PE goes high.
When jumper PL56 is not fitted, 7V will only be applied when ME
is high. This has no effect in isolated mode.