Halytech
hydroSpider2 User’s Manual v1.23
Page 81
Appendix A7.
SDI-12 Command Control
The SDI-12 / RS-485 option adds an additional Control (see section 4.5 Controls), called SDI-12
Command, which sends a custom text string over SDI-12 when the SDI-12 Command Control is
activated and/or deactivated.
This is used in situations where a sensor requires a custom command before or after a reading is
taken. For example: a turbidity sensor may require a wipe command 20 seconds before a reading is
taken. This can be achieved by using the SDI-12 Command control as a warmup on an SDI-12
turbidity sensor channel.
The SDI-12 Command control is configured on the Change Controls page:
The SDI-12 Command control may be selected as a warmup for an input channel, in the same way as
for Switched Power Out.
The “On command” string is sent over SDI-12 when then control activates, and the “Off command” is
sent when the control deactivates.
If you have the LiveSMS software option (see Appendix E LiveSMS (Software Option), the SDI-12
Command control is referenced as ‘CN4’. For example, the SMS command “ON CN4” will send the
SDI-12 On command.
If you have the DNP3 software option (see Appendix G), the SDI-12 Command control can be
accessed as DNP3 binary output point 3.
