Acclima SDI-12 Sensor Reader Kit User Manual

Introducing waveform capture! This user manual or guide is for the Acclima SDI-12 Soil Moisture Sensor Reader Kit.

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Acclima SDI-12 TDR Soil Moisture Sensor Reader Kit


Table of Contents

Electrical safety

Electrical Specification USB Port Input Voltage: 5VDC, ±0.5V Input Current: 400mA Max Solar or External Supply Input 5 -10 VDC SDI-12 Output Signal Voltage: Typically, 0-5VDC Power Output Voltage: 12VDC Short Circuit Current: 400mA ±20%

Operational safety

Before installation of the system, carefully read all manuals and documentation regarding the contents of the packages sent.

Before use, ensure all products are free and clear of any damage, especially to the mainboards and battery terminals. If any damage or defects are visible contact your dealer immediately. Avoid short circuits by keeping any loose metals, screws, or paper clips away from the inner workings of the products. Avoid allowing internal components to be exposed to dust, water, and extreme temperatures. Operating temperature range is 5° C to 45°C.

Environmental operating temperature

Humidity: 0 to 90% RH, Non-condensing -10 to +50°C (+14 to +122°F)

Note: This limitation comes from the lithium-ion cell.


The Acclima RD1200 is a multi-function SDI-12 reader designed to collect readings from SDI-12 devices in a handheld form factor. Optimized for Acclima sensors, it can capture five data point replies to [M!] measurement commands. The Reader can view waveforms and create user-defined sensor thresholds and address sensors without the aid of a Windows PC. The RD-1200 can view statistics and analyze data points on the fly in a user-friendly and easy-to-use form factor.


Rugged Enclosure
2.5 LCD Screen (Mono)
3.7v Lithium-ion Battery
M-12 Connector
Micro USB-B port
Built-in speaker

PSA Before Connecting SDI-12 Devices

The M-12 connector is designed to provide an excellent connection between the reader and the sensor/device. The M-12 connectors are keyed and can only be inserted in one orientation. Once the M-12 plug and connectors are joined, a screw at the top of the plug should be screwed down onto the connector. The screw should only be manipulated by fingers and no tools should ever be used to tighten the two components together. When turning the M-12 locking nut, the screw will stop after only 2 ½ to 3 turns. This is normal and no attempt should be made to screw down the locking nut further after it has become finger tight.

If over-tightening does occur, it will cause damage to the internal components responsible for the connector’s functionality. Efforts have been made to increase the component’s resilience. However, if tools are used to over-tighten and loosen the plug from the M-12 connector, the connector will fail once internal leads have been severed.


Acclima Reader RD1200 Exterior Layout

Acclima SDI-12 Soil Sensor Reader with Labels

Display Icon Tray Legend

Display Icon Legend - Acclima Reader

Delicate components

M-12 Connectors

A sensor with an M-12 connector may be easily plugged directly into the Acclima Reader 1200. Plug the keyed male M-12 connector on the end of the sensor’s cable into the M-12 port on the Acclima Sensor Reader. Tighten the lock nut by turning it clockwise until it is finger tight. The locking nut will only turn around the connector twice.

M-12 Connectors

Note: Over-tightening the M-12 screw may cause damage to the leads on the daughterboard. Stop turning the screw once it is finger tight.

M-12 Connector Easy to Damage

Micro USB

The provided Acclima USB interfaces with the Reader via a micro-USB port. This port is directional, and any device being plugged into the port must be in the right orientation for the device to function. Do not apply to much force inserting the USB device into the Reader or face the risk of damaging the micro-USB port or device.

Ribbon Cables

Ribbon cables are in-use internally in the Reader. No attempts should be taken to manipulate the ribbon cables unless done so by an Acclima repair agent. The ribbon cables and their connectors are extremely delicate and cannot be repaired once damaged by the handler.

Inside of Acclima Reader Showing Ribbon Cables and Micro USB


The 2.5” Monochrome LCD is protected by a hard plastic, coated in a hardened clear epoxy solution. The Reader is not drop-resistant and repeated falls on hard surfaces can cause the LCD to become damaged. We recommend handling the Reader with care.

Acclima SDI-12 Sensor Reader Display Demonstration


Quick Connect Cable

The Acclima Quick Connect Cable is a versatile accessory that allows easy pairing between a variety of different sensors.

Quick Connect Cable by Acclima

The ‘Quick Connect’ component allows un-terminated SDI-12 wires to be inserted into clamps by pressing down onto the clamp to open its port. Once the wire is inserted the clamp can be released and the port will close onto the wire terminal.

Acclima Quick Connect Connections

With the sensor attached to the ‘Quick Connect’ it can be plugged into the ‘Cable’ which has a female SDI plug on one end, and a male M-12 connector on the other end. This allows interfacing between the Quick Connect and/or any other SDI-12 devices with a terminal block to be connected to the Reader.

Last Quick Cable - Acclima

Multi-Port Expander

Using a Multi-port Expander in addition to a Quick Connect Cable, allows for multiple SDI-12 devices to be connected to the Reader at once, via dual wire splices. The Reader can detect up to 62 sensors at once, provided that they are all attached and uniquely addressed.

Multi-port Expander by Acclima

USB Flash Drives

Readers with firmware version 1.7.0 and older, support flash drives with a micro-USB adapter, in the FAT32 (MBR) format.

Readers with firmware version 1.7.1 and newer, support exFAT and FAT32 formats.

Acclima USB Drives

SDI-12 Devices

Sensor Orientation

Sensors should be installed in the region of interest where soil moisture measurements are desired. Acclima sensors measure the average volumetric water content over the length of the sensor rods.

Acclima TDR SDI-12 Soil Moisture Sensor Probing the Soil With a Guide

Sensors can be inserted in any orientation and will produce average readings as follows:

  • Flat/Horizontal: Provides a moisture reading at a discrete depth. This orientation is frequently used when monitoring plants with shallow roots such as turf, or when multiple sensors are used to create a soil moisture profile vs. depth. • Vertical: Provides average moisture reading over a depth of about six inches. Often used when monitoring deeper root systems such as trees.
  • Edge-Horizontal or diagonal: Provides average moisture reading over a variable depth.

We recommend using a waveguide insertion tool to help guide the waveguide/rods into the media wall. This helps to prevent air gaps from forming around the sensor waveguides.

Acclima TDR Probe Guide

For routine sensor insertions, a Wide-Body Sensor Handle can be added as an upgrade option to make regular sensor insertions easier.

Soil Moisture Sensor with Large Handle and Probe Guide

Note: Avoid placing the sensor near rocks or other similar objects. Small roots near the sensor are acceptable and desirable. Avoid large woody roots.

Soil Moisture Sensor Probe Orientation Example 2


Start-Up Sequence

You can turn the Reader on or off at any time by pressing the red power button.

When the Reader is powered on, a boot screen appears containing hardware information. Here, you can see the firmware version, the serial number, and the hardware revision.

Acclima Sensor Reader Screen 1


After the boot logo has passed you will be brought to the home screen. The home screen can also be reached at any time by pressing the ‘home’ button found to the right of the display.

From the home screen, the four primary navigation options are made available. Radio, for GPS settings; Sensor, for sensor settings; Data, for data exportation and Settings, for system configuration settings.

Acclima Sensor Reader Home Screen


After pressing the ‘Settings’ button, the following configurations may be adjusted by the user.

Acclima Sensor Reader Settings Screen

The Beep option allows the user to adjust the speaker volume. This changes the sound level for button presses and sensor readings. The volume can be set to low, high, or off. Press Home>Settings.

The Sleep option adjusts the auto-sleep timer, which is the time that the Reader will be allowed to remain inactive before auto power-off occurs.

The 12/24Hr option changes the clock to run in either standard or military time.

The Set time option allows the user to adjust the clock to correct for Daylight Savings time in their time zone.

Getting Started

General Setup

From the ‘Home’ screen you will see a menu of selections above the blue and white-striped membrane buttons. Press (and release) the soft button under Radio.

Acclima Sensor Reader Radio Button Pressed

Another screen will appear with one menu option ‘GPS OFF’. Press the same button to turn the GPS Radio ON.

Acclima Sensor Reader Turning on the GPS

Subsequently, you will see a stop-watch counter run as the Reader synchronizes with GPS satellites overhead. You must be outside to receive a clear signal.

Try to have a direct line-of-sight to the sky from horizon to horizon when turning on the GPS Radio. If a clear line-of-sight from horizon to horizon isn’t available, try to find an area with a lot of viewable sky. It usually takes 10 – 15 seconds to sync-up and acquire the signal. This may vary depending on your geographic location and other factors such as dense cloud cover and/or tall obstructions such as buildings and trees with dense foliage.

Acclima Sensor Reader Screen GPS Coordinates Set

The time on your reader will be updated after synchronization with GPS satellites (but you may need go to the ‘Home’ screen, choose ‘Settings’ and choose ‘Set time‘ to change your time zone) or adjust for Daylight Savings Time.

Press the ‘Home’ button to return to the main menu.

Sensor Data

Reading the Sensor

A sensor’s details can be found at any time if you are on the home page and the ‘Sensor’ option is pressed. The sensor’s address, model, serial number, hardware, and firmware become visible on the ‘Sensor Setup page 1/3’.

Acclima Sensor Reader Soil Moisture Sensor Settings Screen

To collect SDI-12 device readings with an Acclima Reader. First, verify a firm connection has been established with the sensor. Check that the locking nut has been screwed down correctly and is finger tight. Make sure that the Reader is powered [On] and press the ‘Read Sensor’ button.

Note: If more than one sensor is connected, you will need to enter the Reader into Bussed Mode.

Finger Pushing Acclima Soil Moisture Reader "Read Sensor Button"

The Sensor Reading will be displayed on the Reader. The ‘Sensor Reading’ screen presents the Volumetric Water Content as a percentage, Soil Temperature in Celsius, Permittivity, and Bulk Electrical Conductivity in μS per centimeter.

Acclima Sensor Reader Water Content, Temperature, Permittivity, Conductivity, and Pore Water EC Readings

Note: Temperature accuracy requires the SDI-12 sensor to be buried at least 12 hours in subsurface soil.

A Waveform can be generated on the ‘Sensor Reading’ screen. Press the ‘Show Waveform’. After a few moments, a graph will be generated showing the steps in the reflected EM signal in a high-resolution waveform. For a closer look at the waveform, press ‘Zoom’. You can return to the data by pressing ‘Show Reading’.

Acclima Sensor Reader Screen Showing a Waveform

Sensor Readings

From the Sensor Reading page, you will also have the ‘Stats’ and ‘Analysis’ options. Pressing the ‘Stats’ button will display the number of readings from which the averages, maximums and minimums are taken. To disregard previous readings and begin a new set you will need to press the ‘Clear‘ button on the ‘Reading Statistics’ page.

Acclima Sensor Reader Screen with Stats Button Pushed

Note: At this stage if you have multiple sensors connected, you can collect
readings from the other sensors by pressing ‘Select Sensor’. You can then move to the next sensor by pressing ‘Next Sensor’, then take a new Reading by pressing ‘Read Sensor’.

If you press the ‘Analysis‘ button, you will be presented with the ‘Reading Analysis’ screen which can be useful for indicating the fill level of the soil’s field capacity (FC). The analysis will not provide accurate data unless thresholds are preconfigured by the user.

Acclima Sensor Reader Screen with Analysis Button Pushed

Note: While on any of the four options: ‘Sensor Reading’, ‘Waveform’, ‘Reading Statistics’, or ‘Reading Analysis’ screens, pressing the ‘Read Sensor‘ button will refresh that screen with the newest data being collected and log a new reading.

Acclima Sensor Reader Screen with Thresholds Button Pushed

Press ‘Thresholds’ to adjust sensor thresholds per soil type.


Soil-Types/Water Thresholds

To modify sensor thresholds, first take a sensor reading by pressing the ‘Read Sensor’ button, then press ‘Analysis’ then press the ‘Thresholds’ button. Once on the ‘Set Sensor Thresholds’ page, you can modify the Soil Type, the Field Capacity, and the Managed Allowable Depletion. Change the Soil Type by pressing ‘Change ST’.

Acclima Sensor Reader Screen with Change ST Button Pushed

After pressing ‘Change ST’, you can change the soil type by cycling through the predetermined options in the windowed listing. Use the ‘Next’ and ‘Prev’ buttons to move up or down through the list. Press  ‘Select’ when you have found the soil type that most closely matches the soil that the sensor is being inserted into.

Acclima Sensor Reader Screen Showing Sensor Thresholds with the Select Button Highlighted

Once a soil type has been selected, its Field Capacity and Managed Allowable Depletion can be modified using the [+1, -1 and +0.1] buttons. When the value has been modified, press ‘Done’ to confirm the changes.

Acclima Sensor Reader Screen for Adjusting Soil Field Capacity

Note: Only change the defaulted values after careful consideration has been taken regarding the impacts of the changes.

Field Capacity

Understanding Field Capacity

This wetness scale gives a depiction of the important stages of soil water content starting with Saturation at the top, where soil water content exceeds the surface tension of the soil particles driving the water down into the subsoil, washing away critical nutrients with it and potentially rotting the roots.

Field Capacity is the ideal soil water content that allows moisture, nutrients, and oxygen to stay around the roots.

The Managed Allowable Depletion level is the lowest that soil moisture can go without permanently harming or killing the plant. The customized ‘Allowed depletion limit’ can be set to a chosen value using the navigation buttons if desired.


Each soil type has its own unique characteristics. Acclima has characterized many soil types and has provided default values within the Reader’s operating system that can be used as a guide for irrigation. However, each site will have its unique properties, so it is important to monitor the irrigation levels to best suit the health of the crops being nurtured. Increase or decrease the values found on the thresholds page to better suit the crops’ needs.

Enhanced Analysis Mode

Using the Enhanced analysis mode

Some sensors may utilize an enhanced statistical analysis mode when collecting readings. This Mode may improve readings, by causing the sensor to perform improved statistical processing to better stabilize readings at the cost of power consumption and speed.

To enable Enhanced Analysis mode, press the button for ‘Sensor’ on the home page. Then select the “Tools”.

Acclima Soil Moisture Sensor Reader Screen with Tools Button Pushed

If the detected sensor is compatible with the Enhanced Mode feature, a “Change Mode” button will be present.

On the ‘Sensor Tools’ page, press “Change Mode” to change the analysis mode from ‘Normal’ to “Enhanced”.

 Note: The “Change Mode” option is not available in all sensor models or firmware versions.

Once in the Enhanced Mode, the sensor will remain there until it is changed back to normal mode. Noisy readings will be smoothed due to the number of samples scanned will have been greatly increased.

Note: The “Enhanced Mode” feature is compatible with “Bussed Mode”.

Verify Command

Per Sensor Diagnostic Tool

Sensors displaying odd characteristics can be further troubleshooted with a nifty tool built into the Acclima Reader. This tool runs the V (verify command) found in the SDI-12 protocol.

To perform the ‘Verify’ command. Press the button for ‘Sensor’ on the home page, then press ‘Tools.

Press the “Verify” button, to run the brief sensor diagnostic.

After the verify command is performed, five vital data points will be observed.

Verify Sensor - Outdated Warning

The firmware version is verified against an internal database containing all recent Acclima sensor firmware versions. Power to the sensor is tested to check the cable run for potential issues with the cable. Bulk EC is tested to retrieve any result within operating specification for that sensor model. The sensor’s digitizer is tested to verify samples(readings) are possible. Temperature is also tested to verify the sensor’s thermistor.

Warnings may appear next to these readings and actions should be taken to correct the issues when they arise.

Bussed Mode

Multiple Sensors

By default, only one sensor can be viewed at a time. Enabling “Bussed Mode” allows up to 62 SDI-12 unique devices to be detected at once.

To enable Bussed Mode, simply reach page 2/3 from the ‘Sensor Setup’ by pressing the “-More-” button.

The Address Mode will be set to ‘One Sensor’ by default. Press the “Address Mode” option to change it to ‘Bussed Mode’.

After entering ‘Bussed Mode’, a Bus icon appears in the top left header of the Reader display.

After entering ‘Bussed Mode’ it is recommended to press the ‘Scan’ button to populate the detected sensors.


Note: Each sensor attached must have a unique address or they will not populate and otherwise be invisible in bussed mode.

Sensor Addressing

How to Address SDI-12 Devices

In ‘Bussed Mode’ each sensor connected to the Reader should have a unique sensor address. The sensor’s address allows the reader to differentiate each of the sensors from one another. Each sensor can choose a single identifying character as its ‘address’, which can be any of these types of characters: [0-9], [A-Z] or [a-z]. By default, the address will be set to “0”.

With a single sensor connected in the ‘Sensor Setup’ page press ‘Change Address’.

With a single sensor connected from the home page, press ‘Sensor’, then press ‘Detect’. This action will prompt the sensor to reply with its identifying information or an error. To change the address, press ‘-More-‘ and then press ‘Change Address’.

Acclima SDI-12 Sensor Reader Screen with the Change Address Button Selected

The current address will be displayed, and the new address can be cycled through from 0-9, A-Z or a- z by pressing the [+ Addr] or [- Addr] buttons.

Once the address is chosen, confirm it by pressing ‘Change Addr’.

Acclima SDI-12 Sensor Reader Screen with the Change Addr Button Selected

Press “Home” button, then “Sensor” to see the new address on the “Sensor Setup” 1/3 page.

Acclima SDI-12 Sensor Reader Screen Showing the TDR Sensor Setup Screen

Note: If two or more sensors use the same address, they will not be detected by the Reader, even in Bussed Mode.

Firmware Updates

Updating Sensor Firmware

Sensor firmware updates can be sent to single or bussed sensors anytime a new update has become available.

First, load the update file onto the Acclima USB drive using the folder structure: Acclima\RD1200\Updates.

Insert the USB drive into the micro-USB port on the Reader. The Reader will synchronize and copy the files into the Reader’s memory.

Press the ‘Home’ button, then the ‘Sensor’ option.

On the ‘Sensor Setup page 1/3’. Press the ‘-More-‘ button until you reach ‘Sensor Setup page 3/3’. Then press, “Select Update”.

Here, sensor firmware can be viewed on the page by pressing the “Show Updates” button. The Reader’s memory can be cleared of these updates by pressing “Purge Updates”.

On Sensor Updates (3/3), Press ‘Update Sensor’ to perform a sensor update.

A progress bar will appear, including the selected sensor’s serial number. When the progress is complete, you will see “Confirming” and “Success” after the update has been verified.

Note: If the update speed is too fast or slow, it can be modified by adjusting the BAUD rate.

Update All Sensors at Once

Multiple sensors can be updated at once using the Update All Sensors function.

To update one or more sensors automatically, press the ‘Sensors’ button on the home page. After reaching ‘Sensor Setup page 1/3’ press the “Tools” button.

On the Sensor Tools page press “Update All Sensors”, on the following page a description of the events and a warning to not disconnect the sensor’s or turn off the power to the Reader, while the update is in progress becomes visible.

Press “Begin” to start the update procedure.

The Reader will perform the following tasks in sequence and can be canceled at any time.

  1. Enter the Reader into Bussed mode.
  2. Perform a scan using the aMI command to detect connected sensors.
  3. The Reader will then send packet data to the sensors to determine the most suitable BAUD rate.
  4. The Reader will then deliver the update file found on the Reader to the sensor.
  5. The Reader will auto-adjust the BAUD rate to 2400, if an update fails to load.
  6. When completed, a report is made available that details the number of sensors updated, and those that were not.
    • The report will time out in accordance with the Sleep settings


Changing Update Speeds

When a sensor update fails it can be because of several reasons. The most common is that there may be too many sensors attached or the cables may be too long making it difficult for larger data files to be transmitted to the sensor without error. Adjusting the BAUD rate may improve the ability to transmit the updated file so that the sensor can receive it accordingly.

To change the BAUD rate, Press the ‘Sensor’ button on the homepage, and navigate to the ‘Sensor Updates’ page (3/3) by pressing the ‘-More-‘ button twice.

Acclima SDI-12 TDR Soil Moisture Sensor Reader Setup Screen with the More Button Highlighted

Here, you may press the “BAUD” button.

Acclima SDI-12 TDR Soil Moisture Sensor Reader Sensor Update Screen with the BAUD Button Highlighted

The default BAUD rate is set to 38400, which is the fastest setting available. However, multi-sensor configs, long cable runs and low power draw sensors may not complete updates at the fastest transfer speeds. Pressing the “BAUD” button reduces the BAUD rate until it resets back to the default speed of 38400.  

Acclima SDI-12 TDR Soil Moisture Sensor Reader Sensor Update Screen Showing "Adjusting Update BAUD..." Message

Note: Only drop to the lowest BAUD rate when all other BAUD rates have proven unsuccessful at updating the sensor firmware.

BAUD Rate Speeds Acclima Sensor Reader

Data Exporting

Data Options

From the ‘Home Screen’ press the ‘Data’ button. The ‘Data’ page provides you with the memory usage information (must be at least 1% to show up). You can select your preferred ‘Data Output‘ by pressing that button and toggling through ‘CSV” only, ‘CSV and binary’, or just ‘binary’. This data will then be able to be transferred to your micro-USB drive in the preferred format when it is plugged into the Reader.

The ‘Erase Logs‘ button allows you to erase all log data.

Acclima SDI-12 TDR Soil Moisture Sensor Reader Sensor Data Screen Showing Memory Usage with the Erase Logs Button Highlighted

But the screen requires you to confirm by pressing a ‘YES‘ or ‘NO‘ button. Similarly, the ‘Erase All‘ enables you to erase all log and configuration data, also with a confirmation of ‘YES‘ or ‘NO‘.

Acclima SDI-12 TDR Soil Moisture Sensor Reader Sensor Data Screen Showing Erase all Log Data Message

On the ‘Data’ screen you can access the Data Tag feature screen by pressing ‘Tag‘. The ‘Data Tag’ screen gives you control to group your readings with a specified identification number.

Acclima SDI-12 TDR Soil Moisture Sensor Reader Sensor Data Tag Screen Showing Measurement Grouping

Once a number has been selected all subsequent readings will be associated with that number which will be visible in your exported data.

Acclima USB

Retrieving your data

To retrieve your data for viewing on a computer, insert the micro-USB connector on the 64-gigabyte Acclima thumb drive into the micro-USB port on the side of the Sensor Reader. All the Reader’s records will be transferred to the Thumb drive, which can then be connected to your computer’s USB port for downloading to the PC and viewing in CSV format. Important–Please allow the Reader time to synchronize.

Acclima USB Flash Drive

Do not disconnect the thumb drive until the Reader indicates the synchronization is complete. It will only take a moment to synchronize. Please note that data can only be transferred using a thumb drive. A direct connection between the PC and the Reader will only charge the Reader’s battery, not transfer data.

Upgrading the Reader’s Firmware

If you desire to apply a new firmware update that becomes available for the Sensor Reader on the website, you should download it into the Acclima\RD1200\Updates folder on the thumb drive. Then when you plug the thumb drive into the micro-USB port on the Sensor Reader (while powered on), it will automatically update.Acclima USB Drive Plugged into TDR Soil Moisture Sensor Reader

Caution: Let this process complete uninterrupted by waiting until you see the message ‘Synchronization Complete’ before removing the thumb drive. The Reader will only automatically update if there is a newer firmware file version than it currently has.

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