
30
FLEX Ex 8 Output and HART Analog Modules
Publication
1797-IN003J-EN-P - August 2017
HART Read Back
(1797-OE8H)
The HART Read Back bits show deviations between the analog
measured current value on a loop (by the 1797-OE8H) and the digital
(real) current (sensed by the HART device on its own) received by the
1797-OE8H during HART communication in the background.
When this bit is set (1), it indicates that HART communications are
failing on the associated channel.
Range: 0 = normal, 1 = HART communication failure.
HART
Communication
(1797-OE8H)
Range: 0 = normal, 1 = HART communication is currently occurring.
HART Transmitter
List (1797-OE8H)
When this bit is set (1), it indicates that a HART field device was found
during the rebuild sequence on the associated channel.
Range: 0 = transmitter was not found, 1 = HART transmitter was
found.
Extended
Configuration
(1797-OE8H)
Configuration additions are needed for HART communications. An
extended configuration area is provided. This Extended Configuration
table is configured by writing a CIO or MSG instruction with the
following:
Class =
0x7D
Instance =
Product location on flexbus
(Use 1 for the module located next to the adapter.)
Attribute =
0x65
Service =
Set Attribute Single (0x10).
See on page 32.
HART Status
Indicators
(1797-OE8H)
When this bit is set (1), the indicators are used for HART diagnostic.
Indicator behavior changes to show communication on HART. Each
status indicator represents a HART loop. Flashing yellow indicates that
communication is currently being processed. Solid yellow means that
this device is in the transmitter list.
Field Descriptions