R&S 4200 Series - Page 70

R&S XU 4200 Configuring with the R&S ZS 4200
6166.5368.02.01 3.18
PTT Signaling
PTT can be keyed by a tone with a specified frequency that is present
within AF signal. If the parameter is on, the tone is detected and controls
the PTT function. The tone itself is suppressed within transmitted signal by
a notch filter.
PTT Signaling
Frequency
The frequency of the PTT tone is variable within a specified range.
PTT Signaling
Threshold
The level threshold of the PTT tone detector is variable within specified
range and is related to nominal audio signal level set by “TX Audio Level”.
Note: In case of low absolute levels, the S/N ratio in the system must be
taken into account. Make sure that the S/N ratio does not fall below a
specific value. The applicable value in each case is calculated from the
audio level minus the PTT signaling level for the transmitter. If the setting
with 0 dB in-band signaling is selected, the headroom for the sum level is
reduced by 6 dB.
SQ/RSSI Signaling
SQ can be indicated by a tone with a specified frequency that is present
within AF signal. If the parameter is on, the tone is generated when SQ is
open. A part of AF signal near the SQ tone frequency is suppressed by a
notch filter.
An alternative setting is RSSI signaling. One of four tones within AF range
3 kHz to 3.4 kHz is generated depending on received signal strength. An
appropriate low pass filter is used in order to suppress received AF signal
in the affected AF range.
SQ Signaling
Frequency
The frequency of the SQ tone is variable within a specified range.
SQ/RSSI Signaling
Level
The level of the SQ tone generator is variable within specified range and is
related to nominal audio signal level set by “RX Audio Level”.
Note: In case of low absolute levels, the S/N ratio in the system must be
taken into account. Make sure that the S/N ratio does not fall below a
specific value. The applicable value in each case is calculated from the
audio level minus the signaling level for the receiver. If the setting with 0 dB
in-band signaling is selected, the headroom for the sum level is reduced by
6 dB.
RSSI Output
RSSI analog output can provide various linear curves depending on
received signal strength. Curve “R&S Standard” is predefined, curve “User
defined“ has variable parameters.
RSSI Output Curve
Slope
RSSI analog output: Curve ”User defined” has the slope configurable.
RSSI Output Curve
Offset
RSSI analog output: Curve ”User defined” has the offset configurable.
RSSI Output Curve
Min. Voltage
RSSI analog output: Curve ”User defined” has the minimum output voltage
limit configurable.
RSSI Output Curve
Max. Voltage
RSSI analog output: Curve ”User defined” has the maximum output voltage
limit configurable.