User Manual

Page 19 of 90
CCT24
data rate, hop duration, base slot size and maximum number of remotes. Although the remote slot size
and remote slot time allocation are automatically set in mode 2, the user must predetermine these values
to assure a valid operating configuration. First, set the BaseSlotSize to accommodate the maximum
number of data bytes in a base transmission. Next, determine the RemoteSlotSize required to accommo-
date the maximum number of data bytes in a remote transmission. Use these slot sizes, the maximum
number of remotes that will be used in the network, the RF data rate and the maximum operating range
as inputs to the Calculator to determine the minimum valid HopDuration time. Note that when there are
fewer remotes on the network than the maximum specified, the remotes will automatically be configured
with a bigger RemoteSlotSize parameter.
TDMA fixed (mode 3) - First, set the BaseSlotSize to accommodate the maximum number of data bytes in
a transmission. Next, determine the RemoteSlotSize required to accommodate the maximum number of
data bytes in a remote transmission. Then set the number of remote slots. Use the slot sizes, the number
of remotes, the RF data rate and maximum operating range as inputs to the Calculator to determine the
minimum valid hop duration.
TDMA PTT (mode 4) - use the same procedure as for TDMA fixed mode 3.
The CCT24 base firmware can detect a significant number of invalid configurations and override the
HopDuration parameter to establish a valid configuration. To take advantage of this feature, configure a
CCT24 network in the following order:
1. In all system radios, set the RF_DataRate parameter and save it. Then reset all radios to estab-
lish the new RF data rate.
2. Set the BaseSlotSize and TDMA_MaxSlots or CSMA_RemtSlotSize as needed. Use the default
maximum operating range unless links of more than 20 miles are planned.
3. Set the HopDuration parameter and then read it back. If the HopDuration parameter readout is
different than the value set, the firmware detected an invalid configuration and is overriding it.