Murata Electronics North America DNT500FP Manual Do Utilizador
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©2008 by RF Monolithics, Inc.
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DNT900 - 11/05/08
7.0 Troubleshooting
DNT500 not responding
- make sure DTR is asserted (logic low) to bring the radio out of sleep mode.
Can not enter protocol mode
- make sure the host data rate is correct. The DNT500 defaults to 115.2
kb/s. If using the escape sequence command, make sure a pause of at least 20 ms precedes the escape
sequence.
sequence.
A remote never detects carrier (DCD)
- check that the base station is running, and that the remote Ini-
tialNwkID
parameter is the same as the base station, or is set to 0xFF. Also check that remote is receiv-
ing an adequate signal from the base station.
Carrier is detected, but no data appears to be received
- make sure that RTS is asserted to enable re-
ceive character flow. Make sure the RF transmit power is not on a high settings if the nodes are close
together.
together.
The DNT500 is interfering with other nearby circuits
- It is possible for the RF energy from the DNT500 to
be rectified by nearby circuits that are not shielded for RF, manifesting as a lower frequency pulse noise
signal. If possible, place the antenna at least 1 foot away from the transceiver module, and 3 feet from
other system circuit boards. Place sensitive circuits in a grounded metal casing to keep out RFI.
signal. If possible, place the antenna at least 1 foot away from the transceiver module, and 3 feet from
other system circuit boards. Place sensitive circuits in a grounded metal casing to keep out RFI.
Range is extremely limited
- this is usually a sign of a poor antenna connection or the wrong antenna.
Check that the antenna is firmly connected. If possible, remove any obstructions in the near field of the
antenna (nominal 3 ft radius).
antenna (nominal 3 ft radius).
Transmitting terminal flashes (drops) CTS occasionally
- this indicates that the transmitter is unable to
reliably get its data across. This may be the result of an interfering signal, but most often is caused by
overloading of the network. Adjusting the protocol parameters may increase the network efficiency.
overloading of the network. Adjusting the protocol parameters may increase the network efficiency.
Receiving terminal drops characters periodically
- set the number of retries to a high number and send a
few characters. Check that the transmitted data can get through under these conditions. Sometimes this
symptom is caused by an application that is explicitly dependent on the timing of the received data
stream. The nature of an RF channel imposes a degree of uncertainty in end-to-end transmission delay.
symptom is caused by an application that is explicitly dependent on the timing of the received data
stream. The nature of an RF channel imposes a degree of uncertainty in end-to-end transmission delay.