Sdi-12 communication, About the sdi-12 communication, Power sequence – Campbell Scientific Sentek EnviroSCAN EasyAG SDI-12 Manual v 3.4 User Manual

Page 10

EnviroSMART & EasyAG SDI-12 Probe Manual

Page 5

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. If a break is not received, the probe interface will be placed in sleep mode.

An SDI-12 compatible device will send a break to wake all SDI-12 probe interfaces on the SDI-12 bus

before a command is sent. When this break is received, the EnviroSMART and EasyAG SDI-12

probe interface will then be placed in standby mode, ready to communicate with the controlling device.

The probe interface will remain in standby mode while the command is being processed. If a break (and

valid communication) is not received within fifteen(15) seconds of the last command, the

EnviroSMART and EasyAG SDI-12 probe interface will be placed back into sleep mode.

During a request to sample data, the EnviroSMART and EasyAG SDI-12 probe interface will sample

all sensors on the probe (sampling mode), then be placed into standby mode.

For more information on SDI-12 operation, visit www.sdi-12.org.

Note: Valid communication must have an SDI-12 address included in the command that matches that

of the probe interface, and in the format of a valid SDI-12 command.