Specifications

COMMUNICATIONS
System Scan —
Approximately every 20 seconds the
monitor thermostat attempts to communicate with the asso-
ciated zone controllers and bypass controller. Each associ-
ated device must have a device address lower than the moni-
tor thermostat and must be within the monitor thermostat
scanning range. A monitor thermostat has 32 devices that
can be scanned.
During a system scan the monitor thermostat distributes
information specific to the operation of the system and the
monitor thermostat accumulates zone data from the associ-
ated zone controllers and bypass controller. The address of
the bypass controller must be within the scanning range of
the monitor thermostat.
Network Time Broadcast — The monitor thermo-
stat can broadcast global information on the network. Glo-
bal information is available to each device on the entire
network.
The monitor thermostat must be equipped with an elec-
tronic timeclock for the time, day of the week, and year to
be broadcast to the network. Network time is broadcast two
times per day (1 AM and 1 PM) to synchronize all of the
clocks on the network.
To configure the monitor thermostat for network time broad-
cast turn category 9, option 5 on.
NOTE: There is only on network time broadcaster per sys-
tem. The network time broadcaster can reside on any bus
segment.
When the Outside Air Temperature Sensor option (cat-
egory 5, option 8) is set to ON, outside-air temperature is
broadcast to the network every 15 minutes.
NOTE: If a network consists of multiple monitor thermo-
stats and one of them is the time broadcaster, then it is nec-
essary to configure one of the other monitor thermostats
to request network time. Configure receive network time
(category 9, option 4) to ON. This will cause the time broad-
caster to broadcast time once a minute, which will ensure
that all the monitor thermostats have the correct time. This
is not required if all the monitor thermostats have a
timeclock.
Communication Check — When the Communica-
tion Check is activated, the monitor thermostat verifies that
it can communicate with each device addressed below itself
on the bus. To activate a Communication Check, set the cat-
egory to 7 and the option to 2. Press a left set point button
to toggle the option to ON. When the monitor thermostat
has completed the system scan, the Communication Check
is automatically deactivated.
During a Communication Check, the monitor thermostat
scans consecutive device addresses starting with the device
address one less than the monitor thermostat address. The
monitor thermostat will continue to scan until address 1 is
reached.
The following information is displayed during a Commu-
nication Check:
• the device address being scanned
• if the device has any error
• the type of device
Refer to Table 2 for the Communication Check system
designations.
Table 2 — Communication Check System
Designations
DEVICE TYPE* DESCRIPTION
0 No Device Found
1 VVTT Monitor Thermostat
2 Bypass Controller
3 Zone Controller
4 TEMP System Monitor Thermostat
5 Other CCN Device
*If an "E" is shown in front of the device type designation, the CCN
device at that address has an error.
The 3-digit number in the upper left-hand corner indi-
cates the device address currently being scanned. The
device type and error status designations are located in the
lower right-hand corner of the display.
OCCUPIED MODE OPERATION
Occupied mode is the time period when the monitor ther-
mostat maintains the occupied set point temperatures. Oc-
cupied time periods are configured to define the monitor
thermostat occupancy schedule of the zone. See the Unoc-
cupied Mode Operation section on page 19 for more infor-
mation on selection of time schedules.
During the Occupied mode, the occupied set points:
• can be fully adjusted throughout the occupied set point range
• can be limited to maximum heating and minimum cooling
values within the occupied set point range
The monitor thermostat occupied time periods may be
controlled:
• locally by the monitor thermostat, which will follow its
own programmed unoccupied and occupied time periods
• through communication from another device on the net-
work, which will send the monitor thermostat an occupied
schedule.
Occupied Set Points — The occupied set points es-
tablish the range of acceptable temperatures for the zone dur-
ing a given time period. The heating and cooling tempera-
tures are maintained in the zone controlled by the monitor
thermostat during the Occupied mode. The range of allow-
able temperatures is 50 to 99 F for heating and cooling (de-
pendent on the occupied set point limits).
The left set point buttons control the cooling set point.
Press the top set point button to raise the set point. Press the
bottom set point button to lower the set point. The cooling
set point is displayed in the top left corner of the monitor
thermostat screen.
The right set point buttons control the heating set point.
Press the top set point button to raise the set point. Press the
bottom set point button to lower the set point. The heating
set point is displayed in the bottom right corner of the moni-
tor thermostat screen.
The monitor thermostat will continuously display the set
points unless rotating display or display freeze has been
activated.
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