User's Manual

Troubleshooting
RFI-148 & RFI-900 High Output Power Paging Transmitters User Manual Page 132 of 134
• DISABLED: External Reference: Transmitting is disabled because Radio → Reference → Reference
Mode is set to “External Only” but the external reference cannot be locked to. Either change the
reference mode to allow use of the internal reference or restore the external reference source to within
specification. In either case, the PTT override will clear itself automatically.
G.7.2 Hardware or Auto PTT
When troubleshooting hardware or auto PTT, ensure the following:
• The paging transmitter can transmit with the “Transmit On” routine in Cruise Control.
• Hardware PTT or auto PTT is enabled.
For hardware PTT:
• The correct hardware PTT active level is configured, active low or active high.
• Toggling the hardware PTT state is reflected in the “Ext I/O” table in Cruise Control in the Encoder
Interface group. If this does not work, it indicates a cabling issue with the hardware PTT input.
For auto PTT:
• Toggling the L-bit state is reflected in the “Ext I/O” table in Cruise Control in the Encoder Interface
group. If this does not work, it indicates a cabling issue with the L-bit input.
G.7.3 Profile Definition
If the RFI-900 reports that it is transmitting (Radio → Power → Transmitter Status), yet LIU L-Bit activity
does not produce modulated data, ensure that the selected modulation profile (Encoder Interface → Active
Profile) is not configured to use an external data clock (via the LIU) unless you are providing one (Paging
Protocols → Profiles → Ext. Data Clock).
G.8 Unit Transmits at Low Power
If the unit is transmitting at low power as indicated by the front panel power gauge or transmit power sensor
there could be several causes. Ensure:
• The required transmit power is configured.
• There are no faults active. A unit configured to transmit at a high power level needs similarly higher
sensor cutoffs, see Appendix D.
Otherwise, low transmit power could indicate a hardware failure. If troubleshooting fails, return the unit to
STI Engineering for repair.