Troubleshooting
9-36 9161-A2-GH30-30
April 1998

You can monitor these fields . . . At these settings . . .

ABCD bits (Tx and Rx) for ESF framing or
AB bits (Tx and Rx) for D4 framing Whatever value is currently set
Tip and Ring Leads State
For FXO
For FXS
ToRo – Attached device has both Tip and
Ring leads open
TgRo – Attached device has Tip lead
grounded and Ring lead open
TgR* – Attached device has Tip lead
grounded and Ring lead state is unknown
ToR* – Attached device has Tip lead open
and Ring lead state is unknown
RoT* – Attached device has Ring lead
open and Tip lead state is unknown
RbTo – A battery is applied to the Ring
lead and the Tip lead is open
RbTg – A battery is applied to the Ring
lead and the Tip lead is grounded
TbRg – A battery is applied to the Tip lead
and the Ring lead is grounded
Ring – Ringing voltage applied between
Tip and Ring
RbTo – Ring Lead connected to nominal
–48Vdc battery and Tip lead open
RbTg – Ring Lead connected to nominal
–48Vdc battery and Tip lead grounded
TbRg – Tip Lead connected to nominal
–48Vdc battery and Ring lead grounded
Ring – Ringing voltage applied between
Tip and Ring
Tip and Ring Leads Control State
(FXO only) Loop – Tip and Ring are connected
together
Rgnd – Ring lead is attached to ground
Open – Ring lead is not connected to
either the Tip lead or the ground
Lpgnd – Tip and Ring are connected
together, and Tip is connected to ground
E-lead state (E&M APM only) On
Off
M-lead state (E&M APM only) On
Off