User's Manual

Spread Spectrum Wireless Data Transceiver User Manual
Preliminary GXM Manual Version 0.2 39
PRELIMINARY
Calibrating a Slave in 1PPS Enable/Delay mode
1. Trigger an oscilloscope on the 1 PPS pulse on the DTR line of the Master.
2. Monitor the CD line of the Slave.
3. If the timing on the Slave differs from the Master it may be adjusted via the value in the Slave's 1
PPS Enable/Delay parameter. The difference in time between each incremental integer value is
542.534nS. Changing the parameter to higher values decreases the Slave time delay and
changing the parameter to lower values increases the time delay.
When properly calibrated the CD line of a Slave radio will output a pulse that goes high for about 2mS in
synch with the 1 PPS pulse on the Master radio. The output on the Slave will occur within 20
microseconds of the input to the Master.
Note: When 1 PPS is enabled, the Master must have a 1 PPS pulse on its DTR pin, otherwise the RF
network will not function.
(A)
SLAVE/REPEATER
The Slave/Repeater mode allows a transceiver in a MultiPoint network to switch between Slave and Repeater
functions. When in this mode, a transceiver will repeat any packets sent across the network as well as utilize
the RS232 port. Thus, where one Repeater and one Slave may be required in another vendor’s network,
FreeWave networks require only one transceiver.
Note: To operate a transceiver as a MultiPoint Slave/Repeater, the operation mode must be set to (7)
MultiPoint Repeater and Slave/Repeater set to 1 in the MultiPoint Parameters menu.
(B)
DIAGNOSTICS
This option provides diagnostics data to be viewed at the Master in parallel with application data. The
diagnostic program MUST be run from the Master transceiver. Diagnostics requires the following:
1. The Number Repeaters set to 1 and Diagnostics set to (1 to 128) in the Master.
2. A second computer or serial connection to run the diagnostics software.
3. A diagnostics cable. (Available from FreeWave Technologies.)
4. Diagnostics software. (Available on the User Manual and System Tools CD.)
For more information on Diagnostics, please contact FreeWave Technical Support at [phone].
(C)
SUBNET ID
The Subnet ID function only works in MultiPoint Networks utilizing the Network ID option. In a MultiPoint
Network, a Slave or Repeater will connect with the first Repeater or Master that it hears with the same
Network ID. However, where communications need to be forced to follow a specific path the Subnet ID is
quite useful. Subnet ID is particularly helpful to force two Repeaters in the same network to operate in series
rather than in parallel, or if desired, to force Slaves to communicate to a specific Repeater for load balancing
purposes. Two components exist with regard to the Subnet ID:
1. Rcv Subnet ID. This setting identifies which transceiver a Repeater or Slave will listen to.
2. Xmt Subnet ID. This setting identifies the ID on which this device transmits, and in turn which
devices will listen to it. The Xmt Subnet ID parameter is relevant for MultiPoint Masters and
Repeaters only.
The default (disable) setting for both Rcv and Xmt is F.