Ground Start Trunk; Figure 14: Ground Start Trunk; Table 7: Ground Start Trunk Summary - Mitel SX-200 EL Technician's Handbook

Ground Start Trunk

The Ground Start Trunk serves most PBX-CO connections in an analog
environment.

Table 7: Ground Start Trunk Summary

Signal
Seize
Seize
Acknowledgment
Digits

Figure 14: Ground Start Trunk

Ground Start Trunk PBX
Outgoing
Ring lead goes active. PBX
grounds the ring lead
Tip lead goes active; Audible
Dial Tone generated; ground
returned on tip
Loop Current toggled (Rotary)
or DTMF
Troubleshooting and Repair
Ground Start Trunk
PBX Incoming
Tip lead goes active; 90
Vac is applied to Ring
lead in 2 sec on, 4 sec off
cadence
Tip-Ring leads activated
(shorted); Loop Current
flows in line
-
(Sheet 1 of 2)
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