Multiple One Shot; Retriggerable One Shot - Crestron SIMPL Windows User Manual

Crestron SIMPL Windows
Multiple One Shot Example: screen and drape relays
Touchpanel
fb87
fb88
fb89
fb90
Primer – DOC. 6253
custom control system you would normally want to handle this internally, thus the
user can simply tap a button and the projector would turn on as expected. Shown
above is a One Shot symbol that is triggered off a button press and generates a 4-
second output pulse to drive the IR command. Conveniently, if the video projector
power on function was part of a power up sequence programmed using Buffers, any
time the signal 'vproj_power_on' is driven high, the One Shot will ensure that a 4
second pulse is delivered to the IR driver.

Multiple One Shot

Many times you will find that when you need to use a One Shot to create a fixed-
pulse-length signal, you will need to do the same to other related signals. This can be
accomplished with many One Shot symbols, but because it is so commonplace there
is a special symbol available called the Multiple One Shot.
The Multiple One Shot symbol is essentially a bunch of independent One Shots
grouped into a single symbol. However, notice that each input/output pair represent
the 'trigger' and 'out' of a One Shot symbol; there is no 'trigger*' inputs or 'out*'
outputs on the Multiple One Shot. In addition, all input/output pairs, though
independent of one another, share a common pulse length, specified by the double-
precision 'time' parameter.
press87
Screen_Up
press88
Screen_Down
press89
Drapes_Open
press90
Drapes_Close
pulse_time
When controlling motorized screens and drapes via low-voltage relays, care must be
taken to ensure that the relay closes long enough for the screen or drape
manufacturer's interface to recognize it. In most cases such interfaces require only
about a half-second closure, but you cannot be sure that the user will press the button
for a full half-second. To account for this, a Multiple One Shot symbol can be used
as shown above.

Retriggerable One Shot

Another form of one shot is the Retriggerable One Shot, which is almost functionally
identical to the One Shot. The only difference is that the One Shot symbol will
ignore any changes on 'trigger' or 'trigger*' until 'out' goes low. The Retriggerable
One Shot will recognize a rising-edge on the 'trigger' input (or falling-edge on
'trigger*) even while 'out' is high, causing it to 're-trigger' and start the count all
over again. 'Out' will not go low until the full duration specified by the double
precision 'time' parameter has elapsed since the last trigger.
Multiple One Shots
i1 o1
i2 o2
i3 o3
i4 o4
0.5s
Software
Relay Card
A1
Screen_Up_rly
A2
Screen_Down_rly
A3
Drapes_Open_rly
A4
Drapes_Close_rly
A5
A6
A7
A8
Crestron SIMPL Windows • 53