User's Manual

LGCell Main Hub
3-8 LGCell 4.0 Installation, Operation, and Reference Manual PN 8100-40
620004-0 Rev. B
3.3 LGCell Main Hub Alarm
The two error connections, Major Error and Error Latch, are relay connections. They
are either open or short circuit as shown in the following table.
• Major Error
The Main Hub senses, then latches, major errors, which can be monitored via the
alarm port’s contact closures. Red or unlit (off) LEDs on the front panel indicate
when an alarm is detected. (Refer to Section 10.2 on page 10-2 for help trouble-
shooting using LEDs.)
The major error contact can be brought back to the BTS for alarm monitoring if the
BTS provides +40V DC or less.
Figure 3-8 Monitoring Main Hub Alarms from the BTS
•Error Latch
The error latch provides historical information for troubleshooting when you use
an external alarm monitor. The recommended method of clearing an error latch is
to connect pin 8 (error reset) to pin 1 (+10V) for at least one second. You can
power cycle the unit to clear the error latch, but if you are not monitoring alarms
externally, there is no need to do this. Normal operation of the system will not be
affected by an uncleared error latch.
Operation Major Error Error Latch
Proper Operation Short Circuit Short Circuit
Error Open Circuit Open Circuit
Error Latch indicates that there has been a
major error which was cleared.
Short Circuit Open Circuit
BTS
Main
Hub