Larson Davis SoundAdvisor 831C Reference Manual page 163

• Wireless LTE Gateway, Sierra Wireless
AirLink RV-50, PN COM-RV50-DC-E or COM-
RV50-DC-U
AC/DC Output
Connector: 2.5mm (3/16") Sub-Miniature Phone
Jack, AC Output on RING, DC Output on TIP
AC Output Selections: (1) Off, (2) 0 dB, (3) +20 dB,
(4) +40 dB, and (5) Preamp 10V
Gains of 0, +20 and +40 are relative to
measurement full scale.
AC Output Voltage: For 0 dB through +40 dB
selection: ±2.12 Vpeak Maximum (-16.5dB re. to
input), suitable for LINE inputs
For Preamp selection: ±14.14 Vpeak Maximum
AC Output Impedance: 1kΩ || 1000pF
AC Output Frequency Weighting: No frequency
weighting is applied. Includes input's 0.1Hz high-
pass filter only
DC Output Voltage: 10 mV/dB, +2.2 V maximum,
0V ≈ 0dB & 2V ≈ 200dB
DC Output Impedance: 1kΩ || 1000pF
AC Performance
AC Output Output re
Setting input (dB)
Off
Off
-16.5
Out + 0 dB
-36.5
Out +20 dB
-56.5
Out +40 dB
0.0
Preamp 10V
* Results for typical 377B02 microphone, actually
sensitivity effects results
I/O Connector
Provides External Power, Analog and Digital I/O,
and enhanced capabilities for 831-INT
Mating connector: Hirose ST40X-18S or ST60X-18S
Logic Output: Output driven 0 to +3V through
1kΩ, setting selects function
Logic Input: Input accepts 0 to +3.3V, ≈50kΩ load,
setting selects function
External Power: +10 to +25 V, 500mA, self
resetting fuse
Digital Sensor Port: Synchronous serial port for
PRM2103 and 426A12 metrics
SoundAdvisor Model 831C
0 dB Gain 20 dB Gain
Maximum* Maximum*
(dB re 20 (dB re 20
µPa) µPa)
Off Off
140 120
120 100
100 80
140 120
Preamplifier Control: Digital control lines for
preamplifier calibration check and overload
detection
Windspeed Pulse Input: Input accepts 0 to +3
pulses from anemometer (+5V tolerant), 100kΩ
load, setting selects function
Analog Inputs: 3 channels, 0 to +2.5 V, 100kΩ load,
settings for scale and offset
I/O Connector Pinouts
The pinouts for the I/O Connector are as shown
below:
Pin # Description
1 Ground, Digital and Power
Supply
2 Logic Out 1, Logic Control
Output
3 831 Activity
4 Logic In, Logic Control Input
5 Ground, Digital and Power
Supply
6, 7 Vext, External Power Input
8 SensorClk_L, LD 426A12
digital sensor clock
9 SensorDIO, LD 426A12 digital
sensor data
10 CalOn_H, LD 426A12
calibration signal on
11 Ovld, LD 426A12 overload
detection signal
12 Mains Power Status; OK
when +2.7 V
13 +2.7 V to supply logic
switches
14 Wind Speed In, Pulse input
for wind speed sensors
Signal Type
Ground
Output, 0 to +2.7 V
Output, 0 to +2.7 V
Input, 0 to +5 V
Ground
Input, +10.8 to +30
V, 0.5 A
auto-resetting PTC
fuse
Output, open
drain, +20 V max.
open and 50 mA
max. closed
Bi-directional, +2.7
to +5 V logic, open
drain
Output, 0 to +2.7 V
Input, 0 to +5 V
Input, 0 to +2.7 V
Output, +2.7 V
through 220 
Input, +5 Vpp max.
A-3