User's Manual

General Guidelines
7-8 Troubleshooting
7.1.2. The LF antenna is
detuned by metallic
objects that are in close
proximity.
1. Check the Exciter’s V
TAP
.
2. Reposition the EX21 frames to minimize the
detuning. If this is not practical, consider re-
adjusting the antenna for a larger output or reduce
the C9 threshold. Refer to LF Transmitter Output on
page 5-8
8. The Reader does
not communicate to
the PC.
8.1. No response
from the Reader,
intermittent
response or
garbled response.
8.1.1. RS485 cable wires
are damaged.
1. Isolate the problem area by checking
communication with other Readers located before
or after on the RS485 bus.
2. Inspect the installation specifically looking for
pulled out or damaged cables or bad contacts.
8.1.2. Program in the
Reader is not running due
to internal failure.
1. Get access to the Motherboard and see that Data
LED is OFF.
2. Push RESET button once. Data LED should start
blinking.
3. Push RESET button again. Data LED should go
OFF. If this is not happening, the Reader program is
not running properly and the Reader has to be
replaced.
8.1.3. RS485 interface in
the Reader is damaged.
1. Find all the Readers on the bus that are not
communicating. Perform the following steps with
each of them.
2. Disconnect RS485 bus terminal block/s from the
Motherboard.
3. Locally connect Laptop to the Reader using RS485
Tester and Connecting Board CBD16 (refer to
Figure 5-2 in Chapter 5).
4. Set the line termination jumper on the Motherboard
to Load and RS485 Tester attenuation switch to ON.
Check if you can communicate to the Reader using
the correct address. If not successful, replace the
Reader.
5. Reconnect the bus, place the termination jumper to
its original position and move on to the next Reader.
6. Reapeat steps 2 through 5 until all Readers are
checked.
Problem Symptom Probable Cause Solution