beautypg.com

Wha-gw, Configuration, 3 burst lists – VEGA WHA-GW-WIRELESSHART GATEWAY User Manual

Page 54: Device publishing guidelines

background image

WHA-GW-*

Configuration

22

1981

2011

-0

7

54

5.4.3

Burst Lists

Burst mode is a special communication mode in which a HART slave device sends

responses to a particular HART command without being polled by the master. Normally, a

HART slave device only responds when being polled by the master.

When burst mode is used, a HART slave device can publish data (for example process

values) independently in regular time intervals. Alternatively, data can be published if the

value has changed by a significant amount, has reached a certain threshold level or has

not been updated within a default reporting time.

The gateway maintains a burst message list comprising, for each sub device, the specific

commands currently being published within the WirelessHART network. The burst list is

volatile and therefore reset after power-up or network restart.

Device publishing guidelines

It is recommended that command 48 (Read Additional Device Status) is always
published to ensure caching of the related status information. A publishing interval of
approx. 1 minute is generally the best choice. When configuring WirelessHART
adapters, command 48 allows proper identification and management of a sub-device list
change without direct Host intervention.

Publishing of at least one command should always be enabled at the wireless device
level to allow configuration change detection and automatic device cache invalidation
without direct Host intervention.

Status

Wireless communication status of the device.

: OK, device connected and identified.

: No communication possible.

: Communication possible, device not identified.

Manufacturer

Manufacturer of the selected device.

Analogue Value

Analogue value of the selected device's primary variable.

PV

Primary variable of the selected device.

SV

Secondary variable of the selected device.

TV

Tertiary variable of the selected device.

QV

Quaternary variable of the selected device.

Table 5.4Network Explorer – Instrument List

Displayed
information

Description

Note!

It is important to consider the following publishing guidelines for each device in the wireless

network. Only if publishing of at least one command is activated in each wireless device,

the gateway is able to cache up-to-date device status information, even if no other HOST

activity is ongoing. Up-to-date data is important for efficient device status monitoring.

You will find the publishing parameters of most WirelessHART devices in the "Burst Mode"

menu of the device DTM.