CL4490 User Guide
Version 3.0
Americas: +1-800-492-2320 Option 2
Europe: +44-1628-858-940
Hong Kong: +852-2923-0610
www.lairdtech.com/ramp
17
Laird Technologies
Problem
Solution
Link LED is on, but data
does not get transmitted or
received.
Make sure the CL4490 radio(s) is connected to the correct COM port(s).
Check port settings (host SW could be Laird Configuration Utility or
customer application SW) for correct baud rate, Parity and either
Hardware or No Flow Control. May be due to Flow Control = Xon/Xoff.
Ensure the correct serial cables are installed, that they work properly, and
that null modems are used where necessary. Refer to
RS232
.
Increase the Max Transmit Retries (clients) and/or Broadcast Attempts
(Servers) in small increments until communication is established.
Connect a Null Modem adapter between the client and its host device.
Check the Destination Address setting.
If the host SW has specific timing (RX time out) requirements and Full
Duplex is enabled in the CL4490 radios, disable this feature.
Radios are communicating
but not well, data is
missing.
Try increasing the Max Transmit Retries (for Clients) and/or Broadcast
Attempts (for Servers) in small increments until no packets are missed.
Check the radio LINK LEDs. If the server LINK LED is blinking the server is
resetting. The client LINK LED blinks because it loses synchronization in
the reset. If the client LINK LED is blinking but the server LINK LED is
solid, the client is resetting. Resetting units must be replaced.
Check for possible buffer overflow in the CL4490. If the host is not using
flow control and the 256 byte serial buffer in the CL4490 fills up,
additional serial data from the host is lost and never transmitted. If buffer
overflow is a concern/issue, you may resolve it by switching to the
CL4490 PRO with a 1600 byte serial I/O buffer.
Analyze range and obstacles between the radios. Switching to a higher
gain antenna or raising the antenna height can increase link quality.
Radios were working great
and have recently stopped
working or don’t work as
well.
Check power connections, antennas, and antenna connectors/cables.
Check the Status LEDs on the server and client(s) units:
-
Client(s) LINK LED is OFF.
-
Check antenna and antenna connections.
-
Attempt to read the radio with the Laird Configuration Utility SW.
-
Verify no changes were made to the working radio configuration.
-
If you can’t read the radio and verify its settings, replace the unit.
Server/Client(s) TX LED is stuck ON.
-
Serial interface is blown and unit needs replaced.
Server LINK LED is OFF.
-
Sync to Channel is probably enabled on the server in question and the
Sync Master is either not powered or not in range.
Disable Sync to Channel on server in question OR power on the Sync
master server, make sure it is in range of the server in question.
Verify no changes were made to the server and client(s) configurations
using the Laird Configuration Utility SW.
Check if any changes or updates in the area have produced interference in
the 902-928MHz band. Download the
to
analyze the operating band of the CL4490 radios.
If these tips do not resolve the problem, please email technical support at
call (800) 492-2320, option 2. Hours are Monday through Friday, 8:00 am to 5:00 pm Central Standard Time.