2
017-
03
12
Product Specifications
2.1.4
Gateway Cache Management
The WirelessHART gateway caches parameters and dynamic values of the wireless and wired
subdevices and makes them available to the host. Some commands are automatically cached
by the WirelessHART gateway (upon read). Other commands, for example dynamic values, are
only cached if the respective field device publishes them (upon publishing). See chapter 5.4.2
Burst Lists
The responses to the commands listed in the following table are cached in the WirelessHART
gateway. Commands in the same row have an identical response frame and share the same
cache memory. The write commands (17, 18, 22, 51) will never get an immediate answer, but
their response will be cached (caching upon write-confirmation).
Information Cached by WirelessHART Gateway
Status Information Caching
The WirelessHART gateway caches the device status byte separately for each wireless or
wired device. The device status will be cached from any type of received message, no matter if
from a wired or wireless device, or if it is a "published" or "normal" response.
The extended device status byte is cached in a similar way, but is available only for wireless
devices.
2.2
Scope of Delivery
The scope of delivery comprises the following components
■
Device WHA-GW-*
■
Antenna W-ANT-2400-2DB-ROD (Part. No. 215520)
■
3 stopping plugs for unused cable glands
■
Product documentation
Cache
Command
Description
Static configuration
commands, cached upon
read or upon write
confirmation
0, 11, 21
Read unique identifier
(associated with tag or long
tag)
12, (17)
Read (Write) Message
13, (18)
Read (Write) Short Tag,
Descriptor, Date
20, (22)
Read (Write) Long Tag
50, (51)
Read (Write) Dynamic
Variable Assignments
Dynamic value commands,
cached upon publishing only
1
Read Primary Variable
2
Read Current and Percentage
3
Read All Variables
9
Read Device Variables and
Status
33
Read Device Variables
93
Read Trend
48
Read Additional Device Status
