TM 5-6350-275-24&P
Table 3-7. Intelligent Access Controller DS Maintenance Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. INTELLIGENT ACCESS CONTROLLER FAILURE (FO-9)
Step 1. Monitor LEDs 8 (Sync), 9 (Address sync indicator), and 10 (Address data packet). The LEDs should be
flashing on and off if there is good communication between the IAU and host. This is a software function and indicates
that the IAC has received the sync packet from the host.
If the LEDs do illuminate, go to step 2.
If the LEDs do not illuminate, go to step 3.
Step 2. Monitor LEDs 1 (RTU transmit indicator TX), 2 (RTU receive indicator RX), and 3 (RTU request to send
RTS) on the Intelligent-Access Controller PWA. The LEDs should be flashing on and off if the IAC can communicate
with the RADC or other IACs multi-dropped on the RS-485 line. Also monitor LEDs 4, 5, 6, and 7, for proper
communications between the IAC, IAUs and Entry Card Readers.
If the LEDs flash on and off, the IAC PWA is good.
If the LEDs do not flash on and off, go to step 3.
Step 3. Check the three fuses on the IAC printed wiring assembly.
If any of the fuses are blown, replace with same type fuse and check the IAC for good communications.
If fuse(s) are not blown, go to step 4.
Step 4. Using a multimeter, check for 12 or 24 vac, depending on option, across TB1 pins 1 and 2.
If voltage is present, replace the IAC Printed Wiring Assembly (Para. 3-105).
If voltage is not present, replace the ac step-down transformer (Para. 3-106).
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