Sutron Corporation X-Link Operations & Maintenance Manual, Rev 1.63 5/24/2016 pg. 80
be set up. It does not matter if these measurements are scheduled for the same
time, as X-Link will have to issue multiple commands to the sensors.
When multiple measurements of type SDI-12 are scheduled to go at the same
time, X-Link orders the measurement commands so that concurrent
measurements are commanded first. Non-concurrent measurements occur while
waiting for concurrent results. Also, X-Link is able to recognize when two
different measurement schedules rely on data from a single measurement
command (e.g., measurement 1 commands 0M! and expects parameter 1 while
measurement 2 commands the same and expects parameter 2, both scheduled
at the same time). In such cases, X-Link outputs the measurement command
only once.
7.1.4.7.
SDI-12 Over RS-485
Some sensors such as the Sutron CF Bubbler support SDI-12 over RS-485. This
type of connection uses the hardware RS-485 lines to talk the SDI-12 protocol. It
is used to allow longer cable lengths than would be possible with the SDI-12
hardware lines. Enable this setting if the sensor is connected via RS-485. Do not
forget to provide power to the sensor!
7.1.4.8.
Warmup
If this number is not zero, then the Switched Power line (terminal #10) and VREF
(terminal #19) will be turned on for warmup seconds prior to talking to the SDI-
12 sensor. The line will be kept on until the measurement completes.
You may use Switched Power instead of SDI-12 Power to supply power to the
SDI-12 sensor as long as the sensor does not require to be powered on all the
time. Some sensors (such as the Sutron SDR) need to be powered on all the
time and will not work correctly if powered from the Switched Power line.
If you power the sensor via Switched Power, you must setup the Warmup to at
least one second!
Why use Switched Power instead of SDI-12 Power? To reduce power
consumption of the SDI-12 sensor. SDI-12 Power is turned on all the time, while
Switched Power is only turned on during the measurement if Warmup is not
zero.
Please note that using LinkComm's Send SDI-12 Command window will NOT turn
on Switched Power. However, doing a Live/Forced measurement will.
7.1.4.9.
Analog
Analog measurements involve reading a voltage or current provided by a sensor.
Analog sensors come with instructions that provide information on how to
translate the output voltage into desired units. Translating the analog sensor
