User Guide: Technical
Reference SECTION 5 TROUBLESHOOTING ALARM CONDITIONS FOR
ioLink 4
PRELIMINARY
Customer Support (202) 333-7031
5-3
2. Restart the far end Modem unit. Since the far end Modem unit is the source of the problem and
this alarm is not cleared by restarting the near end, restarting the far end Modem unit will fix the
problem.
5.6 RX Low Signal Power
Low signal power received by the RF unit
1. Check that the Modem units are configured properly:
a. Check that the encoding in the CONFIG menu for each unit is the same.
b. Check the TX code and RX code in the CONFIG menu. The near end TX code
must
be the
same as the RX code of the far end and vice versa. If they are not, the link most likely will not
be able to establish a connection.
2. Make sure that none of the tests in the TEST or ADVANCED menu are on.
3. Check the antenna alignment. Make sure the antenna is aligned properly and that the RF cable
is connected correctly and not damaged. Do this for both the near and far ends of the link.
4. Check that the IF cable is connected properly and not damaged.
5. Verify that the far end Modem unit is on and operating normally. If any alarm conditions exist,
troubleshoot them first to see if that clears the “Low RF Power” alarm.
5.7 RX Low Symbol Power
Low value for power received at the baseband processor
1. Check the RF and Baseband (BB) Signal Level. If both are low (RF<83%, BB<40%) then see
the steps in “RX Low Signal Power.”
Note:
Refer to the RF Input Level vs. RSSI Voltage graph on the next page.
2. Check for possible interference from noise or another system. If the BB Signal level is low
(< 40%), but the RF Signal Level is good (> 83%), the system has either locked onto noise or
another signal, or the ambient noise has become too great for the system to receive signals from
the other end. If there is still a signal level upon powering down the far end Modem unit, then the
near end is picking up noise or another signal.
3. Restart the system. This may cause the system to lock back onto the far end’s signal.
4. Check for possible sources of the interference. See if any other systems have been placed in
the area and find out their operational frequencies and power.
