AeroComm Corporation LX2400 Manuel D’Utilisation
INTERFACIING TO THE LX2400
09/22/00
Preliminary
Preliminary
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4.1.3 CONFIGURATION MODE
The CONFIGURATION MODE is used to read and write the EEPROM -- allowing the Host to set channels,
baud rates, etc. See TABLE 2. While in this mode the LX2400S will not receive any data over the RF link.
TE and CTS are not used.
baud rates, etc. See TABLE 2. While in this mode the LX2400S will not receive any data over the RF link.
TE and CTS are not used.
The Host enters this mode with the following sequence:
1. The Host pulls the TST_MODE pin low.
2. The Host sends the CONFIGURATION START BYTE to the LX2400S.
3. The Host pulls the WR_ENA pin low if writing.
4. The Host sends the EEPROM BYTE READ or the EEPROM BYTE WRITE command.
5. The Host Repeat Steps 3 and 4 until done.
6. The Host drives pins TST_MODE and WR_ENA high.
7. The Host resets the LX2400S.
2. The Host sends the CONFIGURATION START BYTE to the LX2400S.
3. The Host pulls the WR_ENA pin low if writing.
4. The Host sends the EEPROM BYTE READ or the EEPROM BYTE WRITE command.
5. The Host Repeat Steps 3 and 4 until done.
6. The Host drives pins TST_MODE and WR_ENA high.
7. The Host resets the LX2400S.
NOTE: The WR_ENA pin should not be permanently tied low as brownout conditions can corrupt EEPROM
data.
data.
4.1.4 HOPPING MODE
The HOPPING MODE is controlled by the LX2400S. The LX2400S hops approximately every 100ms . During
this time, the LX2400S is changing the frequency it will use to transmit and receive. The LX2400S informs
the Host of the hop by asserting the DSR pin at the connector or by using the XON/XOFF received bytes if
enabled in the EEPROM in the sequence. The DSR pin will frame the hopping procedure. When the Host
software detects the hopping mode during a transmission of a packet, it can be assumed that the packet did
not reach it’s destination and the Host should re-send the packet.
this time, the LX2400S is changing the frequency it will use to transmit and receive. The LX2400S informs
the Host of the hop by asserting the DSR pin at the connector or by using the XON/XOFF received bytes if
enabled in the EEPROM in the sequence. The DSR pin will frame the hopping procedure. When the Host
software detects the hopping mode during a transmission of a packet, it can be assumed that the packet did
not reach it’s destination and the Host should re-send the packet.
4.1.5 BEACON MODE
Beacon mode applies to a LX2400S Server only. In order to synchronize the hopping of all LX2400Ss in a
system, the LX2400S Server will transmit beacon data consisting of system timing information at a periodic
rate. This occurs by default after transceiver reset and initialization. The beacon is transmitted once per
HOP time -- immediately after a HOP occurs. Beacons are not transmitted when the LX2400S Server is
transmitting data from the HOST over the RF link. If the LX2400S Server does not receive data for
approximately 2.5 seconds from the Server Host, the LX2400S Server will resume transmitting Beacons. This
provides continuous synchronization data for the LX2400S Clients. The beacon data is not transmitted or
available to either the Client or Server Host. The beacon takes approximately 2ms to complete. The LX2400S
indicates that it is executing a HOP with the DSR pin and a XON/XOFF sequence if enabled.
system, the LX2400S Server will transmit beacon data consisting of system timing information at a periodic
rate. This occurs by default after transceiver reset and initialization. The beacon is transmitted once per
HOP time -- immediately after a HOP occurs. Beacons are not transmitted when the LX2400S Server is
transmitting data from the HOST over the RF link. If the LX2400S Server does not receive data for
approximately 2.5 seconds from the Server Host, the LX2400S Server will resume transmitting Beacons. This
provides continuous synchronization data for the LX2400S Clients. The beacon data is not transmitted or
available to either the Client or Server Host. The beacon takes approximately 2ms to complete. The LX2400S
indicates that it is executing a HOP with the DSR pin and a XON/XOFF sequence if enabled.
The Server Host can ignore the HOP if the Host software has retry capabilities or can tolerate non-
delivery of data. Empirical testing shows a 3 to 5 percent loss of data when ignoring the HOP indicators.
(See “LX2400S Hopping and Beacon Timing” in Section 4.5)
delivery of data. Empirical testing shows a 3 to 5 percent loss of data when ignoring the HOP indicators.
(See “LX2400S Hopping and Beacon Timing” in Section 4.5)