Campbell AM16/32B Owner's manual

PRODUCT
For comprehensive details, visit: www.campbellsci.com/am16-32b
Overview
The AM16/32B multiplexer significantly increases the number
of sensors thatyou can measure with a Campbell Scientific
data logger. It interfaces with the data logger and adds
terminals so that you can wire additional sensors of almost any
type.
Benefits and Features
Significantly increases the number of sensors the data logger
can measure
Can multiplex 16, 32, or 48 sensors
Supports many types of sensors including thermistors,
potentiometers, strain gages, vibrating wires, reflectometers,
and soil moisture blocks
Decreases the cost of cabling individual sensors on long wire
runs
Allows a relay address to be used to go directly to a specific
channel—reducing power consumption and wear on the
relay switches
Electrical surge protection via gas tubes on all analog I/O,
and varistors or TVS diodes on all other connections
Prevents sensor-cable damage by providing strain relief for
sensor leads and independent routing for sensor shield lines
Eliminates the requirement for dc blocking capacitors for
gypsum soil moisture blocks, significantly reducing sensor
cost
Detailed Description
Depending on sensor type, the AM16/32B can multiplex 16, 32,
or 48 sensors. Up to six AM16/32Bs may be connected to the
same data logger, depending on the number of control ports
and analog inputs available.
The AM16/32B either multiplexes 16 groups of four lines (a
total of 64 lines) through four common (COM) terminals.
Alternatively, a manual switch setting allows the AM16/32B to
multiplex 32 groups of two lines (also a total of 64 lines)
through two COM terminals. A cable connects the common
terminals to data logger analog inputs, excitation channels, or
ground as required by the sensor. The data logger controls the
multiplexer using two control ports, or one control port and
one excitation channel.
Greatly
Increases
Sensor
Capacity
Connects many sensors to single
data logger
16- or 32-Channel Relay Multiplexer
AM16/32B

For comprehensive details, visit: www.campbellsci.com/am16-32b
© 2020 Campbell Scientific, Inc. | 10/16/2020
Electrical Surge Protection
The equipment is protected from electrical surges using gas
tubes on all inputs. A 35 V varistor is connected between the
shield ground and ground lug to provide surge protection. The
Reset, Clock, and +12 V terminals are protected by 18 V TVS
diodes.
Specifications
-NOTE- The protection on the reset, clock,
and +12 V inputs are provided by
18 V TVS diodes.
Power Unregulated 9.6 to 16 Vdc
Scan Advance Occurs on the leading edge of the
clock pulse transition (from below
1.5 V to above 3.3 V)
Minimum Clock Pulse
Width
1 ms
Maximum Actuation Time
for Relay
20 ms
Relay Operation Break before make
Initial Relay Resistance,
Closed
0.1 ohm
Maximum Switching
Current
500 mA
(Switching currents greater than
30 mA [occasional 50 mA current
is acceptable] will degrade the
contact surfaces of the mechanical
relays and increase their
resistance.This will adversely affect
the suitability of these relays to
multiplex low voltage
signals.Although a relay used in
this manner no longer qualifies for
low voltage measurement, it
continues to be useful for
switching currents in excess of 30
mA.)
Maximum Switching
Voltage
50 Vdc
A voltage divider such as the
VDIV10:1 may be needed between
the AM16/32B and the data logger
to stay within the input limits of
the data logger channel.
Minimum Contact Life 5 x 107 operations
Maximum Contact Voltage
Rating
70 V
Maximum Voltage 8 Vdc (clock level)
CE Compliance EN 55022:1998 Class B
EN 61326:1998
Surge Complies with IEC61000-4-5, test
level 3 (±2 kV, 2 ohm coupling
impedance)
Operating Temperature
Range
-55° to +85°C (extended)
-25° to +50°C (standard)
Dimensions 23.9 x 10.2 x 4.6 cm (9.4 x 4.0 x 1.8
in.)
Weight ~680 g (~1.5 lb)
ESD
Air Discharge Complies with IEC61000-4-2, test
level 4 (±15 kV).
Contact Discharge Complies with IEC61000-4-2, test
level 4 (±8 kV).
Typical Current Drain
Quiescent < 210 µA
Active 11 mA (typical in 4x16 mode)
6 mA (typical in 2x32 mode)
Reset Levels
Inactive < 0.9 V
Active 3.3 to 8 V