Crestron electronic RS-232/42 - Manual (Page 18)

Ethernet RS-232/422 COM Module Crestron CEN-COM
Block Diagram of System Incorporating a CEN-COM
For this example, the CEN-COM is set at IP.ID 03. Notice that the IP address of the
CNMSX for this example is 132.149.2.26 and the IP address of the CEN-COM is
132.149.2.25. It is important that the CEN-COM is configured to have, in its static
master list, an entry of IP ID 03 with an IP address of 132.149.2.26 so it can talk
back to the CNMSX. Refer to “add_master” on page 8 and the diagram below.
Bidirectional Communication
Of course, the IP addresses used in this sample program are only an example. Use
the IP addresses in your unique system configuration. Assume that a CT-3500
touchpanel is used to control the state of Zone 1 in a lighting system. Zone 1 can
either be turned ON or OFF or can be ramped UP or DOWN.
To turn the lights on, nine bytes are sent (\x02Z-01-ON\x03). When join #1 on the
touchpanel is pressed, the signal "Lights-Z1-On" goes high. When this signal goes
high, the data is sent out the port to the lighting system. A similar approach is taken
for "Lights-Z1-Off". These buttons have true feedback from the lighting system (i.e.,
when the 16 bytes (\x02Z-01-STATUS-ON\x03) enter the port, the digital signal
"Lights-Z1-On-F" goes high and drives the feedback of join #1 high). In turn, this
lights the feedback for the OFF button on the panel.
In order to ramp the zone, the appropriate command is sent to start the ramping
operation when the UP (“Lights-Z1+” signal) or DOWN (“Lights-Z1-” signal)
button is pressed. When either button is released, the output of the NOR gate goes
high. This, in turn, sends the STOP command (“Lights-Z1-Stop” signal) to the
lighting system, telling it to halt the ramping operation in progress.
It is important to note that the user does not have to define the [TX$] or [RX$] for
the port. If strings are being triggered and matched only in the port, the string
assignment is taken care of by the compiler. If the TX$ is defined, it can be driven by
other string creation symbols (i.e., an Analog to Serial or speed key: TXA). If RX$ is
defined, it can be routed to other string processing symbols (i.e. Serial Gather or
speed key: GATHER). Another typical usage would be if a macro were to drive the
port, then the TX$ and RX$ would come from/go to the macro definition. Refer to
14 • Ethernet RS-232/422 COM Module: CEN-COM Operations Guide - DOC. 5719