Product manual

TAC Xenta Server – Gateway, Technical Manual 10 Using Signals
Schneider Electric Buildings AB, June 2011 83 (184)
04-00124-06-en
10.1.2 Output SNVTs
Output SNVTs are used for sending (propagating) information from
devices on a LonWorks network. The value of the SNVT can be sent
regularly or it can be sent upon change, that is when the signal the
SNVT represents changes.
When you add a SNVT to XBuilder the following dialog box appears
(the Direction has been changed to Output).
The dialog box has a number of controls:
• Name – Output SNVTs are usually called nvo_”XYZ”, to indicate
the direction of the signal, for example nvo_RoomTempSP. A
maximum of 16 characters can be used.
• Type – There are many different types of SNVTs. You select the
type you want from the Type list.
• Direction – When you add an output SNVT you set the Direction
to Output.
• Send – The SNVT is sent regularly from the device if you select
the Send check box.
The value is sent:
• regularly if a time greater than 0 is typed in the Period (s) box
• when the value between the new value and the last value sent
is greater than the value typed in the Delta box and the num-
ber you enter in the Period (s) box is 0.
• on either of the two previous conditions if the values of both
the Period (s) and Delta are greater than 0.
If the Send check box is not selected, the SNVT can only be polled
by other devices; this is not common practice.
• Period (s) – The number you enter in the Period (s) box is the
number of seconds you want to lapse between the SNVT transmis-
sions.
• Backup – By selecting the Backup check box, the momentary
value of the SNVT is stored in the memory of the Xenta 913. If the
Xenta 913 is restarted, the stored value is used until a new value is
detected.