Set Up Global Data
Setup
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global sensor values to all other Global Data applications
on the E2.
As a result, a single sensor can be used by any applica-
tion in any E2 on the network.
Unless you program it otherwise, the E2 always
assumes you will be using Global Data in all your applica-
tions. When you create new applications in the E2, it will
always automatically connect the appropriate application
inputs (except for the spares) to their corresponding
Global Data outputs.
3.10.1 Priority Settings
When selecting the priority for a global sensor input,
there are four settings to choose from.
Primary
Primary inputs are the highest priority
inputs. If a sensor is set up with a primary priority, it
is recognized by all Global Data applications on the
network as the highest priority. The primary provider
sends this input value to the other Global Data appli-
cations in the other E2s, and each E2 immediately
sends that value to all of its own applications that use
the Global Data input.
Only one input of each type may be designated as a
primary on the E2 Network. In other words, if one E2
is acting as the primary provider of the global Out-
door Air Temp, no other E2 on the network may have
a global Outdoor Air Temp sensor with a “primary”
priority.
If using this priority setting, you must enter board and
point settings.
Secondary
Sensors that are set up with secondary
priorities are backup sensors that will be used by all
Global Data applications if the primary sensor fails.
If a global input is set up on an E2 with a secondary
priority, the E2 will not send its value to the other
Global Data applications as long as it is receiving a
primary value of that type from another E2 on the
network. If a secondary provider does not receive a
primary value update at least once every five min-
utes, the secondary provider will assume the primary
sensor has failed, and it will send the secondary
value to all other Global Data applications on the net-
work. These applications will then use the secondary
value in place of the failed primary value.
Secondary providers will continue to send the input
value until the primary provider again sends a valid
update to the other Global Data applications. The
secondary provider would then stop sending the sec-
ondary value, and all Global Data applications would
use the primary value.
If using this priority setting, you must enter board and
point settings.
Example
:
Out of three E2s, an outside air temperature
sensor on E2 A’s I/O Network is set up as the primary
provider of the global Outside Air Temp input. A sim-
ilar sensor is set up on E2 C with a secondary prior-
ity (see
As long as E2 A is capable of broadcasting a valid
temperature value, all three E2s would use E2 A’s
Outside Air Temperature value in their own Global
Data applications.
However, if E2 A loses contact with the sensor, E2 A no
longer has a valid temperature value to send to the
other Global Data applications. After five minutes of
no updates from E2 A, E2 C will consider the pri-
mary Outside Air Temp source to have failed, and it
will begin sending the value of the secondary sensor
to the Global Data applications of the other two E2s.
All E2s would then use this secondary value as Out-
side Air Temperature.
Figure 3-32
- Global Data Priority Example
PRIMARY
PRIMARY
SECONDARY
SECONDARY
PRIMARY USED AS GLOBAL
OUTSIDE AIR TEMP BY ALL E2s
SECONDARY SENSOR USED AS OUTSIDE
AIR TEMP WHEN PRIMARY FAILS
P
P
S
S
P
S
P
S
P
S
P
S
P
S
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Just as there may be only one primary provider for
each input type, there may be only one secondary for
each input type. It is recommended that secondaries
be set up on different E2s than primaries; this way, if
a single controller fails or loses communication with
the other E2s, there will still be a usable input source
for the other E2s.
