Hobo S-VIA-CM14 Specifications

12-Bit 0–5 Volt Input Adapter (S-VIA-CM14) Manual

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Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - TestEquipmentDepot.com

The 12-Bit 0-5 Volt Input Adapter is used for measuring voltage levels and provides a trigger
source voltage for powering external sensors and an open collector trigger. The input adapter
has a plug-in modular connector that allows it to be added easily to a logger.

Specifications

Measurement Range 0 to 5 V

12-Bit 0–5 Volt Input
Adapter

S-VIA-CM14

Items Included:

• Hook and loop tape

• Cable ties

Accuracy ±0.025 V (±0.5% full scale) over full temperature range of -40°C to

Resolution ±1.221 mV

Input Impedance 1 MΩ

Maximum Input Voltage

Sensor Trigger: Open Collector Maximum sink current: 115 mA

Sensor Trigger: Source Voltage: 2.5 V ±2.4%; maximum current: 1 mA

Operating Temperature Range -40°C to 75°C (-40°F to 167°F)

Housing Plastic case; must be placed inside logger enclosure to protect from

User Connection Six-position screw terminal strip (16–30AWG); shielded cable

Dimensions 4.5 x 4.8 x 1.6 cm (1.8 x 1.9 x 0.6 in.)

eight 25 g (0.88 oz)

Number of Data Channels* 1

Measurement Averaging Option Yes

Digital Filtering

Bits per Sample 12

Length of Smart Sensor
Network Cable*

* A single station can accommodate 15 data channels and up to 100 m (328 ft) of smart sensor cable (the digital

communications portion of the sensor cables), although available space in the enclosure may limit the number of
sensors you can attach.

75°C (-40°F to 167°F)

30 V

On time: 12.7 ms ±3%

On time: 12.7 ms ±3%

direct exposure to the weather

recommended with outside diameter of 3.2 to 3.8 mm (0.125 to

0.150 in.)

Automatic digital filtering with 32 readings/sample in 2.4 ms

14 cm (5.5 in.)

The CE Marking identifies this product as complying with all r
directives in the European Union (EU).

elevant

Mounting

Use the self-adhesive hook-and-loop tape included in the package to mount the input adapter
inside the logger enclosure. To mount more than one adapter, use the back of the logger
enclosure door.

For the HOBO Micro Station, you can place the input adapter inside the logger enclosure and
allow it to float freely. It is not necessary to use the hook-and-loop tape.

Mounting Considerations

• If sensor cables are left on the ground, use a conduit to protect against animals, lawn
mowers, exposure to chemicals, etc.

• Refer to the logger manual for additional details on mounting.

7554-C MAN-S-VIA

Attaching Sensor Cables

Insert the cable through the opening at the bottom of the
logger enclosure as described in the logger manual. Be sure to
provide “drip loops” underneath the logger to prevent water
from trickling up the cable and into the logger.

Use the included cable tie to provide strain relief to the cable
(or individual wires), as shown below.

Cable Strain Relief

Sensor Input Connections

The 12-Bit 0–5 Volt Input Adapter utilizes a 6-position screw­terminal block for sensor connections with wire sizes ranging
from 16 to 30AWG. Pin numbers, names and descriptions are as
follows:

Pin # Pin Name Definition

1 GROUND Ground. Used as a common

connection.

2 TRIG. OPEN COLL. Trigger open collector (used to

activate external sensors). Provides a
switched ground for external power
sources (connects to ground when
trigger signal is “true”). Can also be
used in conjunction with external pull­up resistor to trigger external
circuitry. Maximum 30 V, 115 mA. See
Operation for timing diagrams.

3 VOLTAGE INPUT Provides voltage input for sampling.

4 TRIG. SOURCE Trigger source. Provides voltage from

the logger’s battery to power, or
trigger, the external circuitry.
Maximum 2.5 V, 1 mA. See Operation
below for timing diagrams.

5 NC No connection.

6 SHIELD Connects cable shield for noise

suppression and circuit protection.

Typical Setup

A typical voltage transducer setup is shown in the following
diagram with power and shield connections. This configuration
requires the transducer to be continuously powered.

12-Bit 0–5 Volt Input Adapter (S-VIA-CM14) Manual

Transducer Setup

Connecting the Adapter to a logger

To use the 12-Bit 0–5 Volt Input Adapter, stop the logger and
insert the adapter’s modular jack into an available sensor
connection port on the logger.

The logger automatically detects the new input adapter the
next time you launch it. Launch the logger and verify that the
input adapter is functioning correctly. Measurements are
recorded in volts (V). See the logger manual for details.

Operation

The 12-Bit 0–5 Volt Input Adapter uses digital filtering and
optional measurement averaging to reduce the effect of noise
and improve accuracy.

Regardless of whether measurement averaging is used or not,
each sample is comprised of a 10.3 ms (± 3%) warmup period
and a 2.4 ms (± 3%) sample period. During the sample period,
digital filtering is accomplished by taking 32 readings. These
readings are then averaged to produce a single measurement,
as shown in the following diagram:

Measurement Averaging (Not to Scale)

Optional measurement averaging can be selected at launch.
Use measurement averaging if measurements may fluctuate
significantly within the logging interval. Measurement
averaging helps to prevent the sampling error known as
aliasing.

To use measurement averaging, set the Sampling Interval to a
rate that is faster than the logging interval. When measurement
averaging is selected in this way, the adapter takes several
measurements during the logging interval and averages them
to produce a single logged data point. For example, if the
logging interval is 10 minutes and the sampling interval is 1
minute, each recorded data point is the average of 10
measurements.

Note that fast sampling intervals (less than one minute)
significantly reduce battery life.

For more information about sampling intervals, refer to the
logger manual.

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