Rockwell Automation 1794-OF8IH FLEX Isolated Input/Output HART Analog Modules - Manual (Page 102)

Publication 1794-UM065B-EN-E - September 2010
90 Configure Module Messaging
Format a "Get Pass through Message Status" Request
This message is used to query the module for status on a HART message that
has already been initiated. The handle associated with the query is either the
Request Packet Data Structure
(1)
Offset Field Value Definition
0 Module Command 1 = EASY-Hart Format
2 = FULL-Hart Protocol Pass Through Init Command
1 Channel 0…7 Selects Module Channel
2 Handle 0…255 User supplied Message Handle
3 Page Number 0…5 Page number of this Write
4…5 Data Size 0…264 (INT, 2 bytes) Total size of HART Data bytes
needed for complete message
that start at byte offset = 8 (does
not include the 8 header bytes)
6 HART Command
[EASY Hart Format]
Pad Byte
[FULL Hart Protocol]
0…255 or 0 For the "EASY Hart Format", this
field selects the HART
Command.
For the "FULL Hart Protocol" this
field is an unused byte and can
be set to 0.
7 Pad byte 0 Pad byte for 32 bit alignment
8…47
per
page HART data 0…255 For the "EASY Hart Format" this
Data array contains only the
HART Data portion of a HART
message if HART command
selected requires any data.
For the "FULL Hart Protocol" this
Data array contains the complete
fully formatted HART Message
excluding preamble bytes.
(Preamble bytes are not
supported and will cause the
message to fail)
(1) The message handle is supplied by the user and must be unique so that the request does not conflict with any
currently in-progress message. Once a message is completed (Requested and message retrieved or timed out)
the message handle value is again made available for use.