Trigger selection and relationship to Outputs
TRIGGER in
Output "OUT"
Output "OUT"
Output "Delayed"
WIDTH
WIDTH
Width as set on-board
0V
Fig. NL405-3 : Outputs relationship to Input (+ve edge trigger)
TRIGGER in
Output "OUT"
Output "OUT"
Output "Delayed"
WIDTH
WIDTH
Width as set on-board
0V
Fig. NL405-4 : Outputs relationship to Input (-ve edge trigger)
The above two figures show the effect of selecting “+ve edge” or “-ve edge” triggering.
POSITIVE EDGE
(+ve edge) triggering means that the unit will be internally triggered when a rising edge is
seen on the input (IN) socket.
NEGATIVE EDGE
(-ve edge) triggering means that the unit will be internally triggered when a falling edge is
seen on the input (IN) socket.
This can often be used with an external switch closure, such as a foot switch, as long as the DELAYED OUT is
used, the unit is set to RE-TRIGGER and the WIDTH is set longer than the contact bounce time (which will
normally be under 10 ms). The unit may also be triggered when the switch is released (because of poor
contacts) and in this instance an external capacitor across the contacts is called for. This may need to be
found from trial and error but a value of 1µF would be a good starting point.
Users Manual
NeuroLog™ System
NL405
Digitimer Ltd
Page 3 of 5
Copyright © 2003
E-mail:
Tel:
+44 (0)1707 328347;
Fax:
...373153
Website:
www.digitimer.com