Emerson E2 Set Up Applications, Example Setting Up an Outdoor Temperature Sen- sor

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 Figure 10-45).

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.

PRIMARY SECONDARY

P		S
P		P
P	P	P

PRIMARY USED AS GLOBAL

OUTSIDE AIR TEMP BY ALL E2s

PRIMARY		SECONDARY
P		S
S		S
S	S	S

SECONDARY SENSOR USED AS OUTSIDE

AIR TEMP WHEN PRIMARY FAILS

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Figure 10-45- Global Data Priority Example

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.

User This setting means the E2’s global data will read (or be a “User” of) all values coming from the network. This setting is for E2s that are not con- nected to the sensor itself, but read the data that comes from it.

If the application in this E2 will be using primary or secondary inputs from other E2s, then set the priority to “USER.”

Local Only This setting specifies that the input to the global data is read and sent only to within the E2 you are programming. Also, this means that this E2 will not read any Primary or Secondary providers from the network.

If using this priority setting, you must enter board and point settings.

Example: Setting Up an Outdoor Temperature Sen- sor

1.Press (Global Data) and the Status screen opens.

2.Move the cursor to the Outdoor Air Temperature (OAT) Mode, and then choose the priority by scrolling with the ,keys.

3.Press the down arrow button once to the Board and Point section and enter the board and point locations for the sensor.

4.Press  (BACK) to return to the Main Status (Home) screen.

The Outdoor Air Temperature sensor is now set up as a global device in the E2. Other global inputs can be set up using the same method as above.

E2 is now ready to be programmed with applications.

10.18 Set Up Applications

From the Main Status (Home) screen, place the cursor on the application you wish to view and press 

(SETUP). You can also press and select (Setup)

from the Actions Menu to open the Setup screen for your selected application.

Set Up Applications Quick Start • 10-25