Emerson E2 - Manual (Page 136)

10-24 • E2 RX/BX/CX I&O Manual 026-1610 Rev 13 14-SEP-2011
10.17 Set Up Global Data
In a network with multiple E2s, it is often the case that
certain sensors or transducer values will need to be used
by all E2s. A good example of this is outside air tempera-
ture. There is no real need for every E2 to have its own
outside air temperature sensor, and therefore it would be
beneficial if a single sensor could be used by all E2s on the
network.
Navigate to the Global Data screen from the Main
Menu:
1. Press

(System Configuration)
2. Press

(Global Data) to open the Global Data
Status screen.
3. Press  (Setup) to open the Global Data
Setup screen.
The Global Data feature is an enhanced method of
effectively distributing commonly used input values
between multiple E2s. Sensors such as outdoor tempera-
ture and outdoor humidity are set up on an E2 as Global
Data inputs. This E2 then becomes the “provider” of the
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.
10.17.1 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
Figure 10-43 - System Configuration Menu
Figure 10-44 - Global Data Setup Screen