User`s manual

NexSens Technology, Inc.

iSIC User‟s Manual 42

After connecting click on the SDI-12 tab and follow the steps to check sensor communication:

1. First make sure the only SDI-12 sensor connected to the iSIC data logger is the

SDI-12 sensor you want to change the address on.

This is to avoid accidentally changing the wrong SDI-12 sensor or changing this sensor to

an SDI-12 address that already exists.

2. Then send the “?!” command.

The sensor will return n<cr><lf> where n is a number 0-9 and represents the current

address. If a NAK is returned the sensor may not be correctly wired or correctly

operating in SDI-12 mode as the iSIC cannot communicate to it via SDI-12.

If Failed sending command is returned, click on the general tab. Make sure you can

communicate with the data logger. If not, see the data logger communication

troubleshooting sections in the iSIC manual for the corresponding data logger trying to

be connected.

3. Next send the “0I!” command.

Verify that the SDI-12 sensor is correctly connected. Replace 0 with the current SDI-12

address if a different one was returned by ?!.

4. Next send the “0M!” command.

You should see the respond back from the SDI-12 sensor. Wait for the “seconds to

wait” before proceeding. Verify the number of parameters returned matches the

number of parameters listed in iChart for this sensor. Replace 0 with the current

SDI-12 address if a different one was returned by ?!.

The format:

Both the address and number of parameters will be single digit numbers.

5. Next send the “0D0!” command.

You should see the respond back from the SDI-12 sensor. The response will be the

data values separated by „+‟ signs. If not all parameters are returned, send “0D1!”.

Replace 0 with the current SDI-12 address if a different one was returned by ?!.

If you are unable to communicate with the SDI-12 sensor at this point, the only way to

diagnose the issue further is to try the sensor on another known working data logger to see

if it can communicate with the sensor, and to try a known working sensor on the data

logger.

Contact NexSens for a service technician if further communication issues persist.