Emerson Fisher 4320 Instruction Manual page 29

Instruction Manual
D103392X012
Trigger Mode for all messages: Continuous
Update Rate for all messages: 60 seconds
Enabling burst mode provides continuous communication from the wireless position monitor. Burst mode applies only
to the transmission of burst mode data and does not affect the way other data is accessed.
Access to information in the instrument is normally obtained through a wireless network or a Field Communicator. The
Field Communicator or the network may request any of the information that is normally available, even while the
instrument is in burst mode. There is a short pause between each burst mode transmission sent by the instrument,
allowing the Field Communicator or control system to initiate a request. The instrument receives the request,
processes the response message, and then continues "bursting" the burst mode data.
Note
It is recommended that you set burst mode to defaults during initial setup, and make any detailed adjustments to burst
configuration after the device is connected to an operating wireless network.
Burst mode is only supported over the wireless link. No burst transmissions are made over the wired Maintenance Port connection.
To configure a burst message manually select Burst Message 0, Burst Message 1, or Burst Message 2 and use the
sub-menus for detailed configuration. Refer to the Burst Configuration and Diagnostics instruction manual
supplement (D103558X012) for information on detailed burst configuration.
The Burst 'Message Content' setting determines the basic structure of an individual burst message.
The most useful choices for WirelessHART are 'Selected Device Variables' and 'Additional Status'.
The default burst configuration sets up:
D Message 0 to contain 'Selected Device Variables' (HART Command 9 response) with the device PV as the trigger
variable and all available device variables included in the detailed content, including the Loop Current variable,
which is needed by some applications.
D Message 1 to contain 'Additional Status' (HART Command 48 response)
D The update rate set to 60 seconds in Continuous trigger mode.
D Only message 0 is enabled for publishing; this allows you to easily configure the update rate from a gateway
interface.
Note
If your application needs to continuously monitor 'Additional Status' (the content of HART Command 48), enable Message 1
manually.
If an Emerson Gateway is in use, the 'Emerson-Specific' choice can be used. It combines the 4 Dynamic Variables and
the Additional Status in one message. However, it does not include the Loop Current or PV %Range variables. If the
control system requires PV %Range and Loop Current, make sure that these two variables are included in a message
configured for 'Selected Device Variables'.
4320 Position Monitor
February 2013
29