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Specifications
INTER-TEL
®
AXXESS
®
MANUAL VERSION 11.0 – May 2008
Loop Start and Ground Start Trunk Circuit Cards
4.144 LGC and LGC-D Modification: Under certain conditions, previous versions of the
LGC (part no. 550.2309) and the LGC-D (part no. 550.2310) were not able to always properly
detect the ground start signal provided by the central office (CO). A modification to the LGC
and LGC-D has been implemented to correct this problem.
4.145 More specifically, the previous versions of the LGC and LGC-D did not function prop-
erly in ground-start mode when terminated on a CO trunk that had a constant current battery
feed of less than approximately 25mA. The new cards have a built-in 50VDC power supply
and therefore no longer rely on the current from the CO to detect the “ground start” signal.
4.146 A customer site may have this problem if a phone user’s display shows “LINE IS
UNPLUGGED” when attempting to access a ground start trunk on an LGC or LGC-D. To
determine if the card really does have a problem detecting the ground start signal from the CO,
follow these steps:
1. Ensure that the appropriate trunk circuit on the card is programmed for ground start
mode. (Loop start mode is not subject to this problem.)
2. Verify that the card is properly installed and connected.
3. Verify that tip and ring for the trunk circuit are properly connected. Here is a simple
method that works for most cases:
a. At the associated CO block, remove the bridging clips for the trunk.
b. On the telco side of the block, attach a test set (butt set) in monitor mode (on-
hook) to tip and ring.
c. Apply ground to the ring terminal.
d. If you hear dial tone (only while ground is applied), tip and ring are properly con-
nected. Replace the bridging clips and make sure the card can still receive dial
tone.
If you do not hear dial tone, apply ground to the tip terminal. If you now hear dial
tone, tip and ring are reversed.
NOTE: Be sure the test set is in monitor mode. If it is in off-hook mode, sometimes
the line can be seized regardless of the polarity, and the test is invalid.
4.147 Identifying the Modified Cards: Remove the LGC and/or LGC-D and look at the part
number stenciled on the card. Immediately after the part number, there should be a dash (-) and
a single letter contained within a box. This denotes the revision level of the card. The follow-
ing chart shows the revision level of the current, modified cards:
4.148 Improperly paired cards do not work together and the trunks attached to these cards do
not function.
Table 2-10. LGC/LGC-D Revision Levels
Card Part No. ECN No. Revision
LGC 550.2309 4813 826.5223-4D (or higher)
826.5223-5D (or higher)
826.5223-6 (any letter)
LGC-D 550.2310 4814 826.5224-3B (or higher)
826.5224-4B (or higher)
826.5224-5 (any letter)
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