Rockwell Automation AADvance Controller Demo Unit User Manual
Page 86
Demo Unit User Manual (AADvance Controller)
5-20
Document: 553850 Issue 1.2: March 2011
About HART
The AADvance controller is the first Rockwell Automation controller to include
integrated support for HART (Highway Addressable Remote Transducer)
communications. There is no need for separate HART interfaces. The AADvance
Workbench supports HART on analogue input channels; the system implements
revision 5 of the HART specification.
The application program can use HART information to monitor and respond to device
conditions. You can also use HART to carry out maintenance and diagnostic functions
on field devices.
The AADvance Workbench provides a dedicated data structure, T9K_AI_HART, for
application variables that will use the HART functionality. The structure provides the
following information:
The loop current
Four pre-defined dynamic variables, and their associated units
Communication and device status information
Using HART
Make sure that your HART devices support HART command 0 ('read unique ID')
and HART command 3 ('read current and four pre-defined dynamic variables'). The
controller uses these commands to communicate with the HART devices.
The HART loop current variable (available within T9K_AI_HART) is in addition to
the channel variable for the 4 to 20mA loop. You can use the HART loop current
variable for diagnostic checks, for example to compare with the value on the 4 to
20mA loop and react if there is a discrepancy; do not use the HART loop current
variable for a functional safety application.
For more details of HART see the HART Application Guide, created by the HART
Communication Foundation, and their detailed HART specifications. You can
download these documents from www.hartcomm.org.
Configure Analogue Inputs for HART
You configure input channels for HART within the AADvance Workbench. Do the
following:
1) Create HART variables within the Dictionary; set the type to T9K_AI_HART.
You need one variable for each HART device.