DESIGNER’S HANDBOOK 4189350049C EN
Page 156 of 206
In this example, the event lasts
longer than “Timer Min.+Timer Max” time limit, and the relay output will switch OFF
when the time limit is reached.
In general, the timer function can be used to secure a minimum length of the relay output, but also to shorten a very
long event.
If
“Timer MAX” is disabled (it is the same as 0 msec.), then the relay output will always have the same ON time
whenever triggered.
Example:
the XDi is set up to monitor power supply 1 and 2 and provide a caution if power is not OK. The DX1
Relay 1 is set up
to act on the event “XDi caution” and timer mode is used with setting: Timer Min.: 3000 msec. and
Timer Max.: 10,000 msec.
The XDi power supply 1 is shortly interrupted for approx. 1 sec, the XDi issues a caution on the display, and at the
same time relay 1 is activated and is ON for 3 sec. before it goes OFF again.
Later that day power supply drops totally out and again the caution is issued, but this time the relay 1 will stay on
for 3+10 seconds before it goes OFF again. If the power supply 1 lost event is still there, the caution will be
indicated periodically on the XDi display, but the relay output will not go on again before the event has disappeared
for a short while and then re-appear.
The timer function will only react once on a given event.
In the above example, if you desire the relay output to periodically repeat the activation for as long as the event
lasts, then the “Toggle mode” is the right choice, and it will be described in the following.
11.11.3.3
Timer mode with acknowledge
This timer mode works like the normal timer mode. When the Relay time min and max is setup, and the relay is
activated by an event. When the relay is activated, it is possible for a person to deactivate it again, by simply
pushing any of the front buttons shortly.
This function was implemented in connection with the XDi upgrade to platform 2 (including XDi-N). In that
connection front frame with pushbuttons was made available for all XDi models and with front pushbuttons a
manual acknowledge function can sometimes be useful.
In the above example a rudder angle indicator is activating the timer function when the value is inside 300 to 400
(equal to outside SB 30.0° on this 40 degree indicator). The relay activates when the event happens, and it stays
on for minimum 0.5 seconds even if the rudder again moves below 30°. If the rudder continues to be >30° then the
relay is disabled after 10 seconds.
If you don’t need a minimum time, you can disable “Relay timer MIN”.
Acknowledge (Normal):
The operator can disable the relay within the activation timer frame above, by shortly
pushing any of the buttons on the XDi front frame.
Note: If external pushbuttons are connected via an NX1 or 2 module then acknowledge can also be performed from
an external pushbutton.
