Specifications

Crestron SIMPL Windows Software
use of a current sensing device, we have generated a digital signal that represents
whether a VCR is currently turned on or not. That is, when the signal ‘vcr_is_on’ is
high, the VCR is on. Using AND symbols, we can ensure that when the VCR is on,
and the ‘vcr_power_off’ button is pressed, we send the power command to the VCR.
If the VCR is off and the ‘power_off’ button is pressed, we do not want to send the
power command because this would cause the VCR to turn on. We use similar logic
to handle the case where the ‘vcr_power_on’ button is pressed. See the AND
Example for a logic diagram of a complete current sensing program.
AND Example
Buffer Symbol
The Buffer symbol can be thought of as a gate that can be opened or closed, thus
controlling the flow of data. When the gate is open, digital signals are allowed to
flow unaltered from the inputs to the corresponding outputs. When the gate is closed,
all output signals are set to logic low and the input signals have no effect on them.
Opening and closing the ‘gate’ is handled by the enable input terminal. When the
signal connected to this terminal is high, the Buffer is enabled (the gate is open), and
when this signal is low, the symbol is disabled (the gate is closed).
Primer – DOC. 6253 Crestron SIMPL Windows • 41