Specifications

Software Crestron SIMPL Windows
Interlock Example: source selection feedback
Select_DSS
Select_PC_2
Select_PC_1
Select_VCR
Select_DVD "IN1\r"
"IN2\r"
"IN3\r"
"IN4\r"
"IN5\r"
COM Port
clear
set_all
in1
in2
in3
in4
in5
out1
out2
out3
out4
out5
Interlock
press15
press16
press17
press18
press19
fb15
fb16
fb17
fb18
fb19
Touchpanel
Select_VCR_fb
Select_DVD_fb
Select_PC_1_fb
Select_PC_2_fb
Select_DSS_fb
Note that the output signals in this example are being used for feedback only, and are
not being routed to the switcher to select the source. This is because the outputs of
the Interlock are latched, and it is generally considered poor programming to drive
momentary functions (such as an RS-232 command) with a latching signal, even
though in some cases it may work correctly. Since we have momentary signals
already on the input side of the symbol, it is ‘cleaner’ to use these to drive the
switcher.
There is one other reason to use the input signals of the Interlock to drive the
switcher, as opposed to the outputs. If we were to use the output signals, and for
some reason the same source had to be reselected (if for example, someone manually
changed the switcher), this would not work unless another source was selected first
and then the desired source reselected. This is because the RS-232 driver will send
data on the rising edge of the driving signals, and once an output of an Interlock has
gone high, it will not provide a positive-edge unless it is first turned off (by selecting
another input) and then turned back on again.
50 • Crestron SIMPL Windows Primer – DOC. 6253