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devices. The maximum communication distance is 1200 meter, the resistance of 485
terminal is 120 ohms, usually must use terminal resistance when wiring over 300m.
Pay attention to the wiring, 485+ and 485- must be a twisted-pair, in order to reduce
signal interference.
5. Appendix
5.1 Power On Process
Here is a list of the changes of the 8303 power on process indicator light to help users
analyze the steps of the device to help troubleshoot problems.
Table 1 8303-5 Power-on Process (Configured as DHCP Mode)
Time(s)
Status
SYS
LINK
0
～
1
Power on reset
BLUE
OFF
1
～
18
System in startup
GREEN
OFF
18
～
42
The system is started and the
network is initialized
GREEN flash,
frequency is 1 second
OFF
42
～
60
The 4G module initialization
begins
GREEN flash,
frequency is 1 second
GREEN for 1 second,
then off
60
～
82
4G first dial-up connection
BLUE flash, frequency
is 0.2 seconds/time
82
～
126 4G ready for a second dialing
GREEN flash,
frequency is 1 second
OFF
126
～
150
4G the second dialing
BLUE flash, frequency
is 0.2 seconds/time
OFF
150
～
4G in connection
BLUE (with faint
GREEN flash)
The BLUE blinks after
P2P connection.
Table 2 8303 Power-on Process
Time(s) Status
SYS
LINK
0
～
1
Power on reset
BLUE
OFF
