Product Specifications
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Figure 2.2
Network structure and corresponding I/O structure
1. Host application
2. WirelessHART gateway
3. WirelessHART field device (joined first): I/O card 0, channel 0
4. WirelessHART adapter (joined second): I/O card 1, channel 0
5. Wired devices 1...3 connected to WirelessHART adapter: I/O card 1, channel 1
If a WirelessHART device loses its connection to the WirelessHART gateway, it keeps its
position in the list and stays assigned to the respective I/O card. If the connection to the
WirelessHART gateway is re-established, the WirelessHART device has the same
channel/card values that it had before.
The same principle applies to the field devices connected to the WirelessHART adapter. After
communication to the WirelessHART gateway was lost, the field devices regain their previous
position as soon as the connection is re-established.
Long Tag Emulation
The WirelessHART communication protocol uses the long tag to address devices. However,
long tags are only supported by HART 6 devices and newer devices (HART 6 = version 6 of the
HART communication protocol; current version: HART 7). Older devices, for example HART 5
devices, have to be addressed by the "Message" field. If a HART 5 device is connected to the
WirelessHART network using a WirelessHART adapter, the WirelessHART gateway emulates
the long tag with the "Message" field.
Note!
This list is stored in a non-volatile memory of the WirelessHART gateway. The card and
channel number assignment will remain the same after a restart of the WirelessHART gateway
or software.
