RF Neulink NL5000 Rev B0 - Manual (Page 15)

NL5000 User Manual Rev B0 14
other signals at the discriminator output to attempt to determine the presence of a
valid synchronization pattern. This can lead to falsing on noise and signals which
may happen to have the same signature as the synchronization pattern. Although
the error detection and CRC algorithms within the modem are powerful enough to
prevent false data from ever being passed to the host, the modem may miss a
valid packet while trying to decode noise. On the other hand, using the carrier
detect circuit to inhibit signals from passing into the modem until and unless a
carrier of sufficient has been detected makes the modem’s detection of a valid
synchronization pattern slightly more reliable. However, the carrier detect circuit
looks at the RF level of the incoming signal and can open on noise if the noise
level is high enough. This is common on the VHF band. In order to prevent false
carrier detect operation, the carrier detect threshold must be set to the equivalent
of a 20 dB SINAD signal or better.
In general, for best data modem sensitivity, the carrier detect circuit should not be
used, but for best overall throughput i.e. lowest ultimate BER, the carrier detect
circuit should be used. RF Neulink recommends that for most setups, that carrier
detect not be used.
6.0 Configuration Software
To configure the NL6000 Module, the RF NEULINK PC Configuration Software Kit,
NL5000P-PCKT, must be used.
6.1
PC CONFIGURATION SOFTWARE KIT
The user should install the Configuration Software on the host computer. The
RF NEULINK adapter cable connects the modem to a computer’s serial
communications port. Once the cable is hooked up, the user runs the Configuration
Software. This program transfers data between radio and
computer memory.
6.1.1 Configuration Software Kit Contents and Requirements
The Configuration Software Kit for NL5000 (via compatible computer) is model
NL5000P-PCKT. It includes:
1. Configuration Software disk, CD (qty 1).
2. Configuration Software/Power cable-a cable with a DB-15M connector on one
end for connection to the NL5000 modem and a cable to a DB-9F connector for
connection to the host computer and two wires, one red (positive) and one
black (negative) for connections to a power supply.
Note: Ensure that the correct power supply voltage is available for the modem
model used and that said power supply can supply the required current. A
regulated supply is strongly recommended. Unregulated wall-mount supplies are