Campbell SDS-122, User Manual

Page: 15 / 16

User Guide
9
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 operate as 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.
Port A should be set to be the
opposite type
of interface to that to which it is being
connected; e.g. set Port A to DTE when
connecting to a RAD-SRM set to its default
DCE state.
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.