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CHAPTER 5: Operation
5.2 Turning the Unit ON
If you haven’t already, plug the AC power cord of the LDM-MR19.2 itself (for
standalone units) or the RackNest 2/14 (for card units) into a working AC outlet.
The PWR LED should light to indicate that the LDM-MR19.2 is ON. If the local
and remote LDM-MR19.2 units are both operating and passing data, the LEDs
should look like this:
• PWR — ON
• TD — Flashing or OFF
• RD — Flashing or OFF
• RTS — ON or Flashing
• DCD — ON or Flashing
• TEST — OFF
• RPF
(ME760C only)
— OFF
If the LEDs don’t look like this, make sure the unit is receiving power and that
none of the three front-panel pushbuttons are pushed in. If the RPF LED is on,
check the remote site (see
Section 5.4
).
5.3 Operating Procedure
The LDM-MR19.2 can operate entirely unattended. However, you should check
the unit’s LED indicators once in a while to make sure that everything is OK.
While the unit is ON, operating personnel are not exposed to voltages in excess
of 30 volts on its circuit board or on any accessible area of the unit’s DC power
supply. Regardless of this, do not open the unit while it is ON.
5.4 Remote Power Failure (RPF)
The RPF (Remote Power Failure) feature could prove very useful if your
application involves a point-to-point connection between an LDM-MR19.2 card in
a wiring closet or other administrative center and a standalone unit at the source
or destination site. As long as the standalone unit’s internal RPF jumper is set to
ON (the default setting), when a power failure occurs at its site, the unit will use its
last reserves of power to send a special tone to the card at the other end of the line.
