transparent mode is active and ready to transmit SDI-12 commands and display
responses.
Figure 72. Entering SDI-12 Transparent Mode
7.9.18.1.1 SDI-12 Transparent Mode Commands
Commands have three components:
• Sensor address (a) — a single character, and is the first character of the
command. Sensors are usually assigned a default address of zero by the
manufacturer. Wildcard address (?) is used in the Address Query command.
Some manufacturers may allow it to be used in other commands.
• Command body (for example, M1) — an upper case letter (the “command”)
followed by alphanumeric qualifiers.
• Command termination (!) — an exclamation mark.
An active sensor responds to each command. Responses have several standard
forms and terminate with <CR><LF> (carriage return–line feed).
SDI-12 commands and responses are defined by the SDI-12 Support Group
(www.sdi-12.org) and are summarized in the table Standard SDI-12 Command &
Response Set
(p. 269). Sensor manufacturers determine which commands to
support. The most common commands are detailed in the table SDI-12
Commands for Transparent Mode
(p. 269).
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