Geotab IOX-CRS Documentation


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The IOX-CRS allows the CIRUS CONTROLS SpreadSmart Rx™ system to send data through the Geotab® GO device to MyGeotab®.

Key Features

Note: CIRUS CONTROLS retains the right to withdraw Geotab’s access to the SpreadSmart Rx system protocols at any time.

IOX® Specifications and Installation

Hardware Technical Specifications


120 g


Overall Length: 1230 mm L

Widest Point: 36 mm W × 16 mm H


Black, moisture-resistant thermoplastic overmold


CAN: 500 kbps (for daisy chaining)

RS232 Male: 300 to 115200 baud, parity, data bits and flow control

Power Output

Interface: 900 mA @ 12 V/24 V

Daisy Chaining: 2500 mA @ 12 V/24 V

Current Rating

Operating Mode: 30 mA

Sleep Mode: 0.2 mA

Temperature Rating

-40 ℃ to +85 ℃


Keyed mini-USB type-B plug: Daisy chain power and CAN in

Keyed mini-USB type-B socket: Daisy chain power and CAN out

Dual Wire: Red and black wires used for third-party device power. Do NOT use.


Keyed mini-USB plug connects to the GO device or another IOX

Male DB9 connects to a serial device

Compatible Firmware

GO FW XXX.18.24 or higher

Installation Instructions

Professional Installation Required — Installation of the IOX-CRS requires the installer to have sufficient technical knowledge and expertise for mobile device installation and integration into modern vehicles, i.e. Certified Geotab Installer certification or equivalent.

WARNING! Prior to IOX-CRS installation, read and follow GO device installation instructions ( to verify any existing GO device installation is correct in preparation for IOX-CRS installation. Incorrect installation of either the GO device, and/or IOX-CRS can result in loss of vehicle control and serious injury.

WARNING! Prior to IOX-CRS installation, read and follow important safety information, including limitations of use, located following these installation instructions. Always read and follow all safety information to prevent loss of vehicle control and serious injury.


Start with the Geotab GO device unplugged from the vehicle. Remove the IOX expansion port cover on your GO device.


Plug in the 90° USB connector of the IOX to the GO device. Secure the USB connector using a zip tie, being careful not to over tighten it, thereby possibly damaging the USB connector.

NOTE: The USB connector can only be inserted in one orientation (see image).


Connect the male RS232 connector from the IOX-CRS to the female RS232 PC port found on the SpreadSmart Rx controller. Use zip ties to secure the two connectors.

It may be necessary to use an RS232 extension cable in some applications where the SpreadSmart Rx controller is not dash mounted. Please ensure that the extension cable has all pins populated.

NOTE: The DB9 connector will not provide power to any connected third-party device. Power must be supplied separately.


Choose an appropriate mounting location for the SpreadSmart Rx accessory. Keep in mind that the location you have chosen for the GO device will influence the locations available to mount the accessory. This is due to the length of wiring on the IOX-CRS. The installation must not interfere with safe vehicle operation.


The two external red and black wires on the IOX-CRS are NOT required for supplying power to the SpreadSmart Rx. Do not connect these two wires to the SpreadSmart Rx, the vehicle battery/power, or a power source.

WARNING! Red and black wires are not required for this installation. To prevent electrical heat/fire damage to the GO device, vehicle, and/or serious burn injury, do not connect IOX-CRS red or black wires to vehicle power source or any other connection.


Once your connections to the IOX-CRS have been made, connect the GO device and immediately start the vehicle. Your GO device will enter debug mode.


Verify that the device is communicating correctly using a computer or smartphone. Navigate to and enter your name, company, and the Geotab GO device serial number (found at the bottom of the device), and click Log Install.


You will see a screen that displays the current status of the device. If the device is communicating correctly, you will see GREEN lettering with the last valid GPS record. If the text appears in RED, the device is unable to communicate and you must verify the installation.

Termination Shunt IOX V2 Housing.png

You may notice that your IOX comes with a termination shunt installed in the expansion port. If you are installing more than one IOX in a daisy chain you must remove the shunt from each device in line, with the exception of the last IOX connected. That shunt must remain in the last IOX and should be secured with a zip tie.

The use of the shunt in the last IOX is necessary for the GO device to detect and configure the IOX as accurately as possible.

NOTE: Failing to install the shunt in the last IOX could impact IOX communication. It is recommended that you secure the shunt using a zip tie if not already done.

Important Safety Information and Limitations of Use

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WARNING! Do not attempt to install, configure or remove any product from any vehicle while the vehicle is in motion or otherwise in operation. All installation, configuration or removal must be done only in stationary vehicles which are securely parked. Attempting to service units while being operated could result in malfunctions or accidents, leading to death or serious personal injury.

WARNING! All in-vehicle devices and related cabling must be securely fastened and kept clear of all vehicle controls, including gas, brake and clutch pedals. You must inspect devices and cabling on a regular basis to ensure all devices and cabling continue to be securely attached. Loose cabling or devices may impede the use of vehicle controls, resulting in unanticipated acceleration, braking or other loss of vehicle control, which could lead to death or serious personal injury. Improperly fastened in-vehicle devices may detach and impact operators upon sudden acceleration or deceleration, which may cause injury.

WARNING! If at any point after an in-vehicle device is installed a warning light illuminates on the vehicle dash or the vehicle stalls or has a marked drop in performance, shut off the engine, remove the device, and contact your reseller. Continuing to operate a vehicle with these symptoms can cause loss of vehicle control, and serious injury.

WARNING! Your in-vehicle devices must be kept clear of debris, water and other environmental contaminants. Failure to do so may result in units malfunctioning or short-circuiting that can lead to a fire hazard or vehicle damage or serious injury.

WARNING! Do not attempt to remove the devices from the vehicle in which they are originally installed for installation in another vehicle. Not all vehicles share compatibility, and doing so may result in unexpected interactions with your vehicle, including sudden loss of power or shutdown of the vehicle’s engine while in operation or cause your vehicle to operate poorly or erratically and cause death or serious injury and/or vehicle damage.

NOTICE — This product does not contain any user-serviceable parts. Configuration, servicing, and repairs must only be made by an authorized reseller or installer. Unauthorized servicing of these products will void your product warranty.

Copyright © Geotab Inc. 2017-2018 - All Rights Reserved | | Rev 1.1 - 08/2018

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CIRUS and SpreadSmart RX is a trademark of CERTIFIED CIRUS CONTROL SYSTEMS