RF Neulink NL5000 Rev B0 - Manual (Page 22)

NL5000 User Manual Rev B0 21
Modem Protocol Indicates the protocol version number and a button which
opens a menu allowing various parameters of the protocol to be set. These
parameters are detailed in the next section.
6.6.3.5
Protocol
Configuration Software
Acknowledgement required after transmit When checked, the modem
requires an acknowledgement after each transmission or the transmission
will be repeated. The amount of time that the modem will wait for an
acknowledgement and the number of times it will repeat a message can be
set in the Message Retry Limits box and the Time Out Time box on the
Configuration Software page.
Sync Method
Selects which message detection method will be used by the modem for
reception. In the R4S method, the modem looks at raw discriminator audio
for the sync pattern of the transmitted message. In the Carrier Detect
method, the modem looks for the sync pattern, but only after a valid carrier
is detected. See Section 5.7 for details and tradeoffs between these two
methods.
Protocol Mask
The protocol mask determines how close a mask must exist between the
modems ID and the destination ID in the message before accepting and
outputting to the host the message. A ‘1’ for any location in the mask
requires a perfect match, while a ‘0’ means a ‘don’t care’ situation. This is
useful for ‘broadcast’ i.e. one unit transmitting to more than one unit
situation. Note: In broadcast applications, the ‘Acknowledgement after TX’
selection should NOT be selected to prevent multiple units from responding
and interfering with each other.
Dead Carrier before Symbol Sync-Value in 300 ms increments to set the
amount of time a dead carrier should be sent before starting the
transmission of a message. This allows a transmitter to get set on frequency
before the beginning of a message. For the NL5000, this value can be set to
zero.
Delay before Symbol Sync Value in 300 ms increments to set the amount of
delay after the detection of a carrier before starting to look for the beginning
of a message. This parameter is the receiver corollary to the ‘Dead Carrier
before Symbol Sync’ parameter in that it allows for the transmitter to get on
frequency before beginning to look for a message. This parameter is only