Bosch Security Escort SE2000 Series Training Manual page 98

98 en | Troubleshooting transponders, points, receivers, and alert units
Symptoms
All transponders on one bus
in communications failure
High communications error
count.
2017.08 | V2.18.1.0 | DOC
Probable Cause
Power to SE485.
Wire between SE485 and
transponder incorrectly
installed.
Open, short, or grounded
cable from SE485 to first
splice or transponder.
Wrong cable between SE485
and computer.
Bad SE485 Module.
Using third party RS-485
interface.
Wire between SE485 and
transponder incorrectly
installed.
Wrong wire type.
Training Manual
Security Escort
Possible Solutions
Check 9 V DC adapter for
proper voltage. Red Power
LED should be ON (on
SE485).
Check to make sure transmit
from transponder goes to
receive of SE485 and receive
from transponder goes to
transmit on SE485 (RX+ to TX
+, RX- to TX-).
Use VOM to test cable for
short, open or ground. Repair
or replace cable. Also check
for + - pair reversed.
Cable should be a straight
through cable to your
computer serial port
connection. Do not use null
modem cable or cable
marked for printer.
Replace SE485 Module.
Due to changes made for
transient protection,
transformer isolation, and link
busy detection, these signals
are not compatible with third
party RS-485 Interfaces.
Replace with SE485
Check to make sure transmit
from transponder goes to
receive of SE485 and receive
from transponder goes to
transmit on SE485 (RX+ to TX
+, RX- to TX-).
Wire type must be twisted
pair.
Robert Bosch (SEA) Pte Ltd