Rockwell Automation 1794-OF8IH FLEX Isolated Input/Output HART Analog Modules - Manual (Page 81)

Publication 1794-UM065B-EN-E - September 2010
1794-IF8IH and 1794-OF8IH Configuration 69
Digital Mode Fault State (8 of 1 bit each)
Determines how module reacts to faults when channel is used in digital mode.
Range: 0=Reset, 1=Hold Last State
Default: 0
Command 3 Disable (8 of 1 bit)
This bit disables the I/O channel from forwarding the associated HART
Command 3 information from the HART Field device through Cyclic EDT to
the adapter.
This does not disable the module from gathering HART Command 3
information from the HART Field device. As such, HART Command 3
information from the HART Field device is still available via an unconnected
message to the module.
This feature should be exercised by using a Null ForwardOpen method in the
Logix system. That is, the connection to the module and original configuration
has already been accomplished. If utilized, Command 3 Disable should be
utilized under program control (change bit in module configuration tag then
issue reconfiguration message to module) or, more unusually, a manual
operation by an operator (open module profile, change parameter then apply).
When the adapter powers up it reads each module to find out who is out there.
For EDT modules it reads Assembly 125 to gain knowledge of all the
assemblies the module has, whether they are EDT/CEDT and whether they
are GET/SET. If an assembly is a CEDT assembly, the adapter automatically
creates a CEDT entry and drops it into his EDT machine to gather/send this
assembly and store the assembly locally in the adpater. Sometime later a
ForwardOpen configuration arrives by the network for the module. The
adapter proxy strips off a portion (Configuation Part 1) and sends the rest
(Configuration Part 2) on through EDT to the module. Within this module
configuration part are the CMD3 Disable Chx bits. These bits instruct the
module to include or not include CMD3 scanning in its work for the channel.
Users may not have HART devices on every channel so some channels may
want CMD3 disabled. If users do disable scaning, the module also disables the
adapter from including that particular associated assembly in the CEDT
scanning routine by the following method:
The module uses the CMD3 Disable Chx bits to adjust the CEDT entries in
Assembly 125. Initially the Assembly 125 CEDT assemblies (46-53) are
identified as CEDT (0xC0 Cyclic EDT Get or 0x40 Cyclic EDT Set) this
causes the adapter to add them to the CEDT scan. If the module receives a
configuration with CMD3 Disable CHx bits set to "1" (disable), the module