KI-1981A MRC7600—Installation, Programming and Operations Manual
Page 14 of 48 (06/30/98)
Troubleshooting
If troubleshooting is necessary, keep the following in mind:
E&M Interface
Terminals E and M carry signals for both audio and DC logic. The E terminal
connects to Telecenter
®
Ring; while M connects to Telecenter
®
Tip. The M signal is
controlled by the MRC7601. The E signal is controlled by the Telecenter
®
, but is
not used for signaling (.i.e. it is 12 VDC). By connecting a DC voltmeter
between either terminal and ground, you can gain useful troubleshooting
information.
The following table gives the nominal levels for the different Telecenter
®
systems
(actual readings may vary by +/- 0.3 VDC). If you do not see these levels, check
your programming, wiring, verify that the E&M line module is installed in the
LLM and/or the MSM is strapped properly for E&M.
Signal
Systems
VDC
Condition
M to Z
ALL
TC4+
TC21
TC5
+12
+5.7
+1.7
+1.5
Idle
Active - (Red LED On)
Active - (Red LED On)
Active - (Red LED On)
E to Z
All
+12
Always
Tip and Ring Interface
The voltage between the MRC7601 Tip and Ring terminals should be as follows.
(These values are true for all Telecenter
®
systems):
Signal
Systems
VDC
Condition
Tip to Ring
All
+11.5 to +12
Idle
All
+5.5 to +7.5
Active (Red LED On)
Maintenance
Rauland recommends replacement of the battery every 5 years. Use any 3V,
25mm, 250 mAHr lithium coil cell.