SDI-12 Probe Interface Manual Version 3.4 (For firmware revision 1.2.
All rights reserved. No part of this document may be reproduced, transcribed, translated into any language or transmitted in any form electronic or mechanical for any purpose whatsoever without the prior written consent of Sentek Pty Ltd. All intellectual and property rights remain with Sentek Pty Ltd. All information presented is subject to change without notice. 2003 Sentek Pty Ltd EnviroSMART, EasyAG and TriSCAN are registered trademarks of Sentek Pty Ltd.
EnviroSMART® and EasyAG® - Statements of Compliance FCC note of compliance and statement of liability Electro-Magnetic Compliance This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation.
EnviroSMART & EasyAG SDI-12 Probe Manual Table of Contents The EnviroSMART® and EasyAG® SDI-12 Probe Interface .............................1 About the SDI-12 probe interface .......................................................................................................................1 What is SDI-12?.......................................................................................................................................................
EnviroSMART & EasyAG SDI-12 Probe Manual Table of Figures Figure 1: Intelligent Probe Configuration Utility software......................................................................... 2 Figure 2: EnviroSMART® and EasyAG® SDI-12 probe interface communication power sequence ........ 6 Figure 3: Voltage levels on the SDI-12 line during an Acknowledge Active command (a!)........................ 7 Figure 4: EnviroSMART® SDI-12 probe interface board layout...................................................
EnviroSMART & EasyAG SDI-12 Probe Manual The EnviroSMART® and EasyAG® SDI-12 Probe Interface About the SDI-12 probe interface This section provides information about the EnviroSMART and EasyAG SDI-12 probe interfaces. What is SDI-12? SDI-12 (Serial Digital Interface at 1200 baud) is a standard communication protocol, allowing connection of multiple sensors to an SDI-12 compatible data logger.
EnviroSMART & EasyAG SDI-12 Probe Manual What is the Intelligent Probe Configuration Utility? The Intelligent Probe Configuration Utility is provided to configure the EnviroSMART and EasyAG SDI-12 probe interfaces with depth location, normalization values (air and water counts) and calibration information for each sensor installed on the probe.
EnviroSMART & EasyAG SDI-12 Probe Manual All sensor information must be valid before the configuration can be written to the probe. Normalizing Sensors Normalization is the setting of the range over which the sensor is effective. For example, soil moisture sensors have a range bounded by the 2 extremes, air and water. The normalization process is necessary to adjust for any variances that may occur during the production of the sensor.
EnviroSMART & EasyAG SDI-12 Probe Manual SDI-12 Probe Interface About setting up the EnviroSMART® and EasyAG® SDI-12 probe interface This section provides information on setting up the EnviroSMART and EasyAG SDI-12 probe interfaces. Why do I need to configure the SDI-12 probe interface? The EnviroSMART and EasyAG SDI-12 probe interface must be configured to ensure valid information is reported to the data logger when data is requested.
EnviroSMART & EasyAG SDI-12 Probe Manual SDI-12 Communication About the SDI-12 Communication This section provides information about the SDI-12 communication protocol used by the EnviroSMART and EasyAG SDI-12 probe interfaces. Power Sequence Figure 2 shows the power consumption modes of the EnviroSMART and EasyAG SDI-12 probe interface during communication with an SDI-12 compatible device. The EnviroSMART and EasyAG SDI-12 probe interface, at power up, will remain in standby mode for fifteen(15) seconds.
EnviroSMART & EasyAG SDI-12 Probe Manual sleep mode EnviroSMART or EasyAG SDI-12 probe interface in sleep mode 250µA break standby mode break 15 second timeout 66mA valid communication received? no yes standby mode process command (including response) 66mA sampling mode sample sensors 100mA (Moisture) 130mA (Salinity) Figure 2: EnviroSMART® and EasyAG® SDI-12 probe interface communication power sequence Timing Figure 3 shows voltage levels on the SDI-12 line during transmission of an Acknowledge
EnviroSMART & EasyAG SDI-12 Probe Manual In this example shown in Figure 3, there is no inter-character gap sent by the SDI-12 probe interface. The start bit for the second character follows immediately after the stop bit (marking) from the first character. Note: The EnviroSMART and EasyAG SDI-12 probe interface will permit up to 4 bit-times between characters before rejecting the command. ?=3F !=21 3.5V Spacing Level Marking 8.4 mS Break Min 12 mS Marking Level Bit Number: Bit Value: 1 1.
EnviroSMART & EasyAG SDI-12 Probe Manual Data Reading The EnviroSMART and EasyAG SDI-12 probe interfaces accept the Start Measurement command (aM! or aMn!) and Start Concurrent Measurement command (aC! or aCn!) for obtaining calibrated values from the probes sensors. Note: The EnviroSMART and EasyAG SDI-12 probe interfaces do not support the Continuous Measurement command (aRn!). The probe will respond with its address followed by in response to this command.
EnviroSMART & EasyAG SDI-12 Probe Manual Command aM! Response a0139 The response indicates that 9 soil moisture values will be available within a time of 13 seconds. After approximately 10 seconds the probe will issue a Service Request (a, where “a” is the probe address). The controlling device will then issue Send Data commands (aDn!) to read the values. Command aD0! aD1! aD2! Response a+001.0000+001.1234+000.0200 a+000.1234+000.0000+123.1234 a+010.1200+000.1243+044.
EnviroSMART & EasyAG SDI-12 Probe Manual aD0! aD1! aD2! a+001.0000+001.1234+000.0200 a+000.1234+000.0000+123.1234 a+010.1200+000.1243+044.8750 If there are more than 9 salinity values, a further Start Measurement command (aM! or aMn!) must be issued. Command aM3! Response a0187 The response indicates that another 7 salinity values will be available within a time of 18 seconds.
EnviroSMART & EasyAG SDI-12 Probe Manual Soil Moisture Values (aC!) The Start Concurrent Measurement command (aC! or aCn!) “aC!” allows all soil moisture values to be sampled with a single command. Values are gathered in the same way as for the Start Measurement command (aM! or aMn!), but the Send Data command (aDn!) may return up to eight(8) values. Command aC! Response A02116 The response indicates that 16 soil moisture values will be available after a time of 21 seconds.
EnviroSMART & EasyAG SDI-12 Probe Manual Note: Refer to notes on Start Measurement (aM! or aMn!) command above. Soil Moisture Configuration Values (aC4!, aC5! and aC6!) The Start Concurrent Measurement commands (aC! or aCn!) “aC4!”, “aC5!” and “aC6!” allow all soil moisture A, B and C constants to be sampled with a single command. Values are gathered in the same way as for the Start Measurement command (aM! or aMn!), but the Send Data command (aDn!) may return up to eight(8) values.
EnviroSMART & EasyAG SDI-12 Probe Manual The response indicates that 16 C constant values will be available immediately. The controlling device will then issue Send Data commands (aDn!) to read the values. Command aD0! aD1! Response a+000.0285+000.0285+000.0285+000.0285+000.0285 +000.0285+000.0285+000.0285 a+000.0285+000.0285+000.0285+000.0285+000.0285 +000.0285+000.0285+000.0285 Note: The EnviroSMART and EasyAG SDI-12 probe interface will not issue a service request for this command.
EnviroSMART & EasyAG SDI-12 Probe Manual The response indicates that 16 salinity depth values will be available immediately. The controlling device will then issue Send Data commands (aDn!) to read the values. Command aD0! Response a+010.0000+020.0000+030.0000+040.0000+050.0000 +060.0000+070.0000+080.0000 a+090.0000+100.0000+110.0000+120.0000+130.0000 +140.0000+150.0000+160.0000 aD1! Note: The EnviroSMART and EasyAG SDI-12 probe interface will not issue a service request for this command.
EnviroSMART & EasyAG SDI-12 Probe Manual Supported Commands SDI-12 Commands Supported The following commands are supported by the EnviroSMART and EasyAG SDI-12 probe interfaces: Command Name Response a! Acknowledge Active a The probe interface address aI! Send Identification allccccccccmmmmmmvvvxxxxxxxxxxxx Identification information aAb! Change Address a The probe interface address aM! Start Measurement atttn Delay (ttt) in seconds and number of values (n) up
EnviroSMART & EasyAG SDI-12 Probe Manual Extended Commands Supported There are no extended commands supported by the EnviroSMART and EasyAG SDI-12 probe interface.
EnviroSMART & EasyAG SDI-12 Probe Manual EnviroSMART® Technical Specifications SDI-12 Version supported: Version 1.2 PCB Revision: 2.
EnviroSMART & EasyAG SDI-12 Probe Manual Total current consumption: 250µA @ sleep 66mA @ standby 105mA @ sampling (Moisture) 130mA @ sampling (TriSCAN™) Time to sample 1 sensor: 1.2 seconds maximum (Moisture only) 2.
EnviroSMART & EasyAG SDI-12 Probe Manual EasyAG® Technical Specifications SDI-12 Version supported: Version 1.2 PCB Revision: 0.0 SDI-12 Interface connector type: Brand: Phoenix Contact MPT0.5/3-2.54 SDI-12 Interface pin configuration: 1 +Vin 2 Ground 3 SDI-12 data Voltage Supply (SDI-12 +Vin): 9 – 20 Volts DC (12 Volts DC @ >200mA recommended) SDI-12 Interface baud rate: 1200 bits per second TTL Interface connector type: Brand: JST B 6B-PH-K (Socket) PHR- 6 (Plug), SPH-002T-P0.
EnviroSMART & EasyAG SDI-12 Probe Manual Total current consumption: 250µA @ sleep 66mA @ standby 102mA @ sampling (Moisture) 126mA @ sampling (TriSCAN™) Time to sample 1 sensor: 1.2 seconds maximum (Moisture only) 2.
EnviroSMART & EasyAG SDI-12 Probe Manual Circuit Information VSUP MF-R090 +V IN 1 SMCJ22A 0V 2 1 VCC 5 N81-A350X GND SDI-12 510R 3 MF-R010 510R Phoenix EMC 1,5/3-G-3,5 (EnviroSMART) MPT0.5/3-2.54 (EasyAG) 3.
EnviroSMART & EasyAG SDI-12 Probe Manual Revision Information EnviroSMART® Revision Information PCB Revision 1.2 • Interface connector type: Brand: Phoenix Contact FK-MC 0,5/5-ST-2,5 (Socket) • MC 0,5/5-G-2,5 (Plug) Interface pin configuration: 1. +Vin 2. Reserved 3. Reserved 4. Ground 5. SDI-12 data 5 SDI-12 data Ground N.C N.C 1 6 1 +Vin TTL Port Figure 8: EnviroSMART® SDI-12 probe interface old revision board layout EasyAG® Revision Information No previous revisions.
EnviroSMART & EasyAG SDI-12 Probe Manual Appendix A – Soil Moisture Management What soil volume does the SDI-12 probe interface measure at a single sensor? At a single depth level, a sensor on the probe records volumetric water content from a soil volume outside the access tube, which has a sphere of influence of: ⇒ 10cm vertical height ⇒ 5-10cm radial distance from the outer wall of the access tube What are the water units? If a calibrated sensor reads one(1) millimetre, there is one(1) millimetre of vol
EnviroSMART & EasyAG SDI-12 Probe Manual Figure 10: Measurements using imperial units What part of the soil profile do multiple sensors on the probe measure? Probes in almost all cases have more than one sensor to monitor the depth of irrigation and the depth of the root zone. The first sensor is located at a soil depth of 10cm (if the datum plate of the top cap sits on ground level) measuring effectively the soil profile slice of 5-15cm depth.
EnviroSMART & EasyAG SDI-12 Probe Manual Appendix B – Salinity Management Please refer to the “TriSCAN™ Agronomic User Manual” Copyright © 1991 – 2003 Sentek Pty Ltd All rights reserved Page 25
