Campbell AM16B, AM32B Product Manual

AM16/32B

Relay Multiplexer

Revision

Copyright ©
Campbell Scientific, Inc.

: 7/18

1987 – 2018

Limited Warranty

“Products manufactured by CSI are warranted by CSI to be free from defects in
materials and workmanship under normal use and service for twelve months
from the date of shipment unless otherwise specified in the corresponding
product manual. (Product manuals are available for review online at

www.campbellsci.com.) Products not manufactured by CSI, but that are resold

by CSI, are warranted only to the limits extended by the original manufacturer.
Batteries, fine-wire thermocouples, desiccant, and other consumables have no
warranty. CSI’s obligation under this warranty is limited to repairing or
replacing (at CSI’s option) defective Products, which shall be the sole and
exclusive remedy under this warranty. The Customer assumes all costs of
removing, reinstalling, and shipping defective Products to CSI. CSI will return
such Products by surface carrier prepaid within the continental United States of
America. To all other locations, CSI will return such Products best way CIP
(port of entry) per Incoterms ® 2010. This warranty shall not apply to any
Products which have been subjected to modification, misuse, neglect, improper
service, accidents of nature, or shipping damage. This warranty is in lieu of all
other warranties, expressed or implied. The warranty for installation services
performed by CSI such as programming to customer specifications, electrical
connections to Products manufactured by CSI, and Product specific training, is
part of CSI's product warranty. CSI EXPRESSLY DISCLAIMS AND

EXCLUDES ANY IMPLIED WARRANTIES OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE. CSI hereby disclaims,
to the fullest extent allowed by applicable law, any and all warranties and
conditions with respect to the Products, whether express, implied or
statutory, other than those expressly provided herein.”

Assistance

Products may not be returned without prior authorization. The following
contact information is for US and international customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle repairs
for customers within their territories. Please visit www.campbellsci.com to
determine which Campbell Scientific company serves your country.

To obtain a Returned Materials Authorization (RMA) number, contact
CAMPBELL SCIENTIFIC, INC., phone [phone]. Please write the
issued RMA number clearly on the outside of the shipping container. Campbell
Scientific’s shipping address is:

CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784

For all returns, the customer must fill out a “Statement of Product Cleanliness
and Decontamination” form and comply with the requirements specified in it.
The form is available from our website at www.campbellsci.com/repair. A
completed form must be either emailed to [e-mail] or faxed to
[phone]. Campbell Scientific is unable to process any returns until we
receive this form. If the form is not received within three days of product
receipt or is incomplete, the product will be returned to the customer at the
customer’s expense. Campbell Scientific reserves the right to refuse service on
products that were exposed to contaminants that may cause health or safety
concerns for our employees.

Safety

DANGER — MANY HAZARDS ARE ASSOCIATED WITH INSTALLING, USING, MAINTAINING, AND WORKING ON OR AROUND

TRIPODS, TOWERS, AND ANY ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES,
ANTENNAS, ETC. FAILURE TO PROPERLY AND COMPLETELY ASSEMBLE, INSTALL, OPERATE, USE, AND MAINTAIN TRIPODS,

TOWERS, AND ATTACHMENTS, AND FAILURE TO HEED WARNINGS, INCREASES THE RISK OF DEATH, ACCIDENT, SERIOUS
INJURY, PROPERTY DAMAGE, AND PRODUCT FAILURE. TAKE ALL REASONABLE PRECAUTIONS TO AVOID THESE HAZARDS.
CHECK WITH YOUR ORGANIZATION'S SAFETY COORDINATOR (OR POLICY) FOR PROCEDURES AND REQUIRED PROTECTIVE
EQUIPMENT PRIOR TO PERFORMING ANY WORK.

Use tripods, towers, and attachments to tripods and towers only for purposes for which they are designed. Do not exceed design limits.
Be familiar and comply with all instructions provided in product manuals. Manuals are available at www.campbellsci.com or by
telephoning [phone] (USA). You are responsible for conformance with governing codes and regulations, including safety
regulations, and the integrity and location of structures or land to which towers, tripods, and any attachments are attached. Installation
sites should be evaluated and approved by a qualified engineer. If questions or concerns arise regarding installation, use, or
maintenance of tripods, towers, attachments, or electrical connections, consult with a licensed and qualified engineer or electrician.

General

• Prior to performing site or installation work, obtain required approvals and permits. Comply

with all governing structure-height regulations, such as those of the FAA in the USA.

• Use only qualified personnel for installation, use, and maintenance of tripods and towers, and

any attachments to tripods and towers. The use of licensed and qualified contractors is highly
recommended.

• Read all applicable instructions carefully and understand procedures thoroughly before

beginning work.

• Wear a hardhat and eye protection, and take other appropriate safety precautions while

working on or around tripods and towers.

• Do not climb tripods or towers at any time, and prohibit climbing by other persons. Take

reasonable precautions to secure tripod and tower sites from trespassers.

• Use only manufacturer recommended parts, materials, and tools.

Utility and Electrical

• You can be killed or sustain serious bodily injury if the tripod, tower, or attachments you are

installing, constructing, using, or maintaining, or a tool, stake, or anchor, come in contact with
overhead or underground utility lines.

• Maintain a distance of at least one-and-one-half times structure height, 20 feet, or the distance

required by applicable law, whichever is greater, between overhead utility lines and the
structure (tripod, tower, attachments, or tools).

• Prior to performing site or installation work, inform all utility companies and have all

underground utilities marked.

• Comply with all electrical codes. Electrical equipment and related grounding devices should be

installed by a licensed and qualified electrician.

Elevated Work and Weather

• Exercise extreme caution when performing elevated work.

• Use appropriate equipment and safety practices.

• During installation and maintenance, keep tower and tripod sites clear of un-trained or non-

essential personnel. Take precautions to prevent elevated tools and objects from dropping.

• Do not perform any work in inclement weather, including wind, rain, snow, lightning, etc.

Maintenance

• Periodically (at least yearly) check for wear and damage, including corrosion, stress cracks,

frayed cables, loose cable clamps, cable tightness, etc. and take necessary corrective actions.

• Periodically (at least yearly) check electrical ground connections.

WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS,
THE CUSTOMER ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR
MAINTENANCE OF TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS,
ENCLOSURES, ANTENNAS, ETC.

Table of Contents

PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.

1. Introduction ................................................................ 1

1.1 Typical Applications ............................................................................ 1

1.2 Compatibility ....................................................................................... 1

2. Precautions ................................................................ 2

3. Initial Inspection ......................................................... 2

4. QuickStart ................................................................... 2

5. Overview ..................................................................... 9

6. AM16/32B Specifications ......................................... 10

7. Installation ................................................................ 12

7.1 Wiring to Datalogger ......................................................................... 12

7.1.1 Control Terminals ....................................................................... 12

7.1.2 COM Terminals .......................................................................... 12

7.1.3 Measurement Terminals .............................................................. 13

7.2 Grounding .......................................................................................... 13

7.3 Power Supply ..................................................................................... 14

7.4 Installation in Enclosure ..................................................................... 14

8. Operation .................................................................. 14

8.1 Programming ...................................................................................... 15

8.1.1 Short Cut Programs ..................................................................... 15

8.1.2 Using CRBasic MuxSelect() Instruction ..................................... 17

8.1.3 General Programming Considerations ........................................ 17

8.1.4 Mixed Sensor Types ................................................................... 17

8.2 General Measurement Considerations ............................................... 17

8.2.1 Long Cable Lengths .................................................................... 17

8.2.2 Completion Resistors .................................................................. 17

8.2.3 Contact Degradation ................................................................... 18

Appendices

A. Importing Short Cut Code Into CRBasic Editor ... A-1

B. Example Measurements and Programs ................ B-1

B.1 Single-Ended Voltage Measurement ................................................ B-1

B.2 Differential Voltage Measurement ................................................... B-4

B.3 Half-Bridge Measurement ................................................................ B-6

i

Table of Contents

Full-Bridge Measurement ................................................................ B-8

B.4

B.5 CR5000 Program Example ............................................................ B-12

C. Thermocouple Measurement ................................. C-1

C.1 Measurement Considerations .......................................................... C-1

C.1.1 Reference Junction ................................................................... C-1

C.1.2 Datalogger Reference ............................................................... C-1

C.1.3 AM16/32B Reference .............................................................. C-2

C.1.4 Thermal Gradients .................................................................... C-3

Figures

5-1. AM16/32B Relay Multiplexer ........................................................... 10

7-1. Example of AM16/32B-to-datalogger signal connection (4x16

mode) ............................................................................................. 13

B-1. Typical single-ended voltage measurement connection .................. B-1

B-2. Typical differential voltage measurement connection ..................... B-4

B-3. Typical half-bridge measurement connection ................................. B-6

B-4. Full-bridge measurement ................................................................. B-8

C-1. Differential thermocouple measurement with reference junction

at the datalogger ........................................................................... C-2

C-2. Differential thermocouple measurement with reference junction

at the AM16/32B (using 107-L thermistor) ................................. C-2

C-3. AM16/32B aluminum cover plate ................................................... C-3

Tables

7-1. Control Terminal Function and Datalogger Connection ................... 12

B-1. Wiring for Single-Ended Voltage Measurements CRBasic

Example ....................................................................................... B-2

B-2. Wiring for Differential Voltage Measurements CRBasic

Example ....................................................................................... B-4

B-3. Wiring for Campbell Scientific 107 Temperature Sensors

CRBasic Example ........................................................................ B-7

B-4. Wiring for Load Cells CRBasic Example ....................................... B-9

B-5. Wiring for CS616 Sensor CRBasic Example ................................ B-10

B-6. Wiring for CR5000 Program Example .......................................... B-12

CRBasic Examples

B-1. Single Ended Voltage Measurements Using MuxSelect() .............. B-2

B-2. Single-Ended Voltage Measurements ............................................. B-3

B-3. Differential Voltage Measurements Using MuxSelect() ................. B-5

B-4. Differential Voltage Measurements ................................................ B-5

B-5. Campbell Scientific 107 Temperature Sensors ............................... B-7

B-6. Load Cells ....................................................................................... B-9

B-7. CS616 Sensors............................................................................... B-11

B-8. CR5000 Program Example ............................................................ B-12

ii

NOTE

AM16/32B Relay Multiplexer

1. Introduction

The primary function of the AM16/32B multiplexer is to increase the number
of sensors that can be measured by CR300-series, CR6-series, CR800-series,
CR1000, CR1000X-series, CR3000, and CR5000 dataloggers. The AM16/32B
is positioned between the sensors and the datalogger. Mechanical relays in the
AM16/32B connect each of the sensor channels in turn to a common output
destined for the datalogger. The user program advances the multiplexer
through the sensor channels, making measurements and storing data.

A slide switch located on the AM16/32B top panel selects one of two modes of
operation. In 2x32 mode, the multiplexer adds 32 terminal pairs. In 4x16 mode,
it adds 16 terminal groups with four terminals each. The datalogger program is
written according to the selected mode and the sensors to be measured.

The maximum number of sensors multiplexed by an AM16/32B depends
primarily on the type(s) of sensors to be measured.

This manual provides information for CRBasic dataloggers and
AM16/32Bs with serial numbers greater than 5056.

For Edlog datalogger support or for specifications for AM16/32Bs
with serial numbers less than 5056, see an older version of this
manual at www.campbellsci.com/old-manuals

1.1 Typical Applications

The AM16/32B is intended for use in applications where more terminals are
needed than the datalogger has available. Most commonly, the AM16/32B is
used to multiplex analog sensor signals, although it can also be used to
multiplex switched excitations, continuous analog outputs, or even certain
pulse counting measurements (those that require only intermittent sampling). It
is also possible to multiplex sensors of different, but compatible, types (see
Section 8.1.4, Mixed Sensor Types

1.2 Compatibility

The AM16/32B is compatible with Campbell Scientific’s CR300-series,
CR6-series, CR800-series, CR1000, CR1000X-series, CR3000, and CR5000
dataloggers.

The AM16/32B is compatible with a wide variety of commercially available
sensors. As long as relay contact current maximums are not exceeded (see
Section 2, Precautions
time, system compatibility for a specific sensor is determined by sensor­datalogger compatibility.

.

(p. 17)).

(p. 2)), and no more than four lines are switched at a

1

AM16/32B Relay Multiplexer

NOTE

2. Precautions

The AM16/32B is also compatible with the CDM-A108 and
CDM-A116 24-bit analog input modules by using the CRBasic
CDM_MuxSelect() instruction. Refer to the CRBasic Help for
information on using the AM16/32B with these modules. The
CDM-A100 Series manual includes a sample program for the
CDM-A108 and the AM16/32B.

The AM16/32B is not designed to multiplex power. Its intended function is to
switch low-level analog signals. Switched currents in excess of 30 mA will
degrade the relay contacts involved, rendering that channel unsuitable for
further low-level analog measurement. Customers who need to switch power
are directed to Campbell Scientific’s SDM-CD16AC, A6REL-12, or
A21REL-12 relays.

Changing the setting of the mode switch from 4x16 to 2x32 connects COM
ODD H to COM EVEN H and also COM ODD L to COM EVEN L. After
wiring the AM16/32B, exercise due care to avoid inadvertently putting excess
voltage on a line or short-circuiting a power supply, which might damage
connected devices such as datalogger, wiring panel, sensor, or multiplexer, and
which would not be covered under warranty.

3. Initial Inspection

• The AM16/32B ships with:

o 4 grommets

o 4 screws

• Upon receipt of the AM16/32B, inspect the packaging and contents for

damage. File damage claims with the shipping company.

• Immediately check package contents. Thoroughly check all packaging

material for product that may be concealed. Check model number, part
numbers, and product descriptions against the shipping documents. Model
or part numbers are found on each product. On cables, the number is often
found at the end of the cable that connects to the measurement device.
Ensure that the expected lengths of cables were received. Contact
Campbell Scientific immediately if there are any discrepancies.

4. QuickStart

Short Cut is an easy way to program your datalogger to make measurements
through an AM16/32B multiplexer. Short Cut is included in installations of
LoggerNet, PC400, PC200W, and RTDAQ. It is also available as a download
on www.campbellsci.com.

2

This section will guide you through programming a datalogger to measure 6
Campbell Scientific 107 temperature sensors as an example for creating a
program using a multiplexer. With minor changes, these steps can apply to
other measurements and dataloggers.

Open Short Cut. From the

LoggerNet toolbar, click Program |
Short Cut. In PC200W and PC400,

click on the Short Cut icon.

Select Create New Program.

AM16/32B Relay Multiplexer

NOTE: The first time Short Cut is
run, a prompt will appear asking for
a choice of first notch frequency.
Select 60 Hz Noise Rejection for
the United States and areas using
60 Hz ac voltage. Select 50 Hz
Noise Rejection for most of Europe
and areas that operate at 50 Hz.

3

AM16/32B Relay Multiplexer

A second prompt lists sensor
support options. Campbell
Scientific, Inc. (US) is probably the
best fit if you are outside Europe.

To change the first notch frequency
or sensor support option for future
programs, use the Program menu.

Select your datalogger model in the
Datalogger Model drop-down list.
This tutorial uses the CR6-series
datalogger.

4

The Progress Bar is used to track
the progress of the program being
created. It is also used to jump
directly to any step in the
programming process.

The next window displays
Available Sensors and Devices.
Expand a folder by clicking on the

symbol. Expand the Devices
folder, then double-click on the
AM16/32 to add it to the Selected
panel.

AM16/32B Relay Multiplexer

5

AM16/32B Relay Multiplexer

When the AM16/32 multiplexer is
added as a device, a new AM16/32
tab will appear at the bottom of the
Available Sensors and Devices
pane. With the AM16/32 tab
selected, select the Sensors |
Temperature subfolder.
Double-click on 107 Temperature
Probe (4-wire).

In the resulting window, enter the
number of 107 temperature probes
to measure on this AM16/32B
multiplexer. For this tutorial, enter 6
as the number of 107 (4-wire)
sensors to add. Click OK in the
dialog window to accept the default
name of T107_C and the default
units of Deg C.

6

In the Scan Interval box, enter how
frequently the datalogger should
make measurements. When
measuring with an AM16/32B
multiplexer, we recommend an
interval of 30 seconds or longer.
Enter 30 and select Seconds.

Click Next.

AM16/32B Relay Multiplexer

After adding the measurements,
click Wiring Diagram to see how
the sensors are to be wired to the
AM16/32B and how the AM16/32B
is to be wired to the datalogger. The
datalogger tab (CR6 Series in this
example) shows the connection
between the AM16/32B and the
datalogger, and the AM16/32 tab
shows the sensor connection to the
AM16/32B.

7