Crestron Electronics 4 Series - Run Multiple Programs

192 • 4-Series™ Control Systems Product Manual — Doc. 8559B
Run Multiple Programs
4-Series processors run multiple programs simultaneously to allow programmers to
independently develop and run device specific programs for AV, lighting, HVAC, security, and so
forth. As a system grows, processing resources can easily be shifted from one 4-Series processor
to another without rewriting any code.
Device Registration Considerations
To keep the system running seamlessly, consider the following when stopping and starting
programs:
l
To ensure that devices are registered by the correct programs, note that programs restart
in ascending order by program slot when the device is rebooted or when the progreset
command is entered. For example, Program 1 starts before Program 2.
l
Since most devices can only be registered by a single program, the first program to try
registering the device succeeds. Subsequent attempts to register the device fail. If
Program 1 registers a device, then Program 2 is not able to register it. Devices that fail to
register can often be found in the log listed for that particular program that attempted to
register it. For Ethernet devices, the IP Table will generally have a status of "NOT REG"
due to a previous program registering the device first.
NOTE: This behavior does not apply when programs are started and stopped
individually. For example, if the programmer stops all programs and restarts Program
10 before Program 1, Program 10 registers the device first.
l
There are exceptions to this rule described in the bullet above, as some devices, slots, and
ports can be registered by multiple programs. Refer to the following table to determine
whether a particular control system slot or port is exclusive (can only be registered by one
program) or shareable (can be registered by multiple programs).
NOTE:Within the following table, "shareable" means that all programs can access the
device. "Exclusive" means only one program can ever register the device. Additional
details provided in the Status column describe exceptions for how this device is
handled by multiple programs.
Port and Slot Sharing
Slot or Port Status
Expansion card
cages
Shareable
BACnet Exclusive
Built-in
COMport
Slots are sharable but ports are exclusive (For example, Program 1 can
register COM 2 while Program 5 registers COM 1, but both programs cannot
register COM 2 at once.)