II - DCE FEL ČVUT v Praze

Modifying the
parameters of the
field devices
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04
Remember that the field devices signal each change in the parameters as a
configuration change to the HART analog module. This leads to a diagnostic
interrupt on the programmable controller, provided this option is enabled. It
is advisable to disable the diagnostic interrupt during configuration and
parameter assignment. You can do this when you assign parameters to the
HART analog module, see Section 4.4.
4.3.2 Operating Phase of HART Analog Module and Field Devices
Operating phase
In the operating phase you must distinguish between the cyclic return of user
data, acyclic HART interventions, and cyclic HART communication.
The cyclic user data, for example measured values, are obtained from the
programmable logic controller (PROFIBUS DP master class 1): The user
data area exists for this purpose. In the case of the HART analog input
module, this is the input area; in the case of the HART analog output
module, it is the output area.
Acyclic intervention for diagnostics and modifying the parameters of the
field devices is carried out with the SIMATIC PDM parameter assignment
tool (on PROFIBUS DP master class 2) or with a HART hand-held device
using HART commands and HART responses.
You can establish cyclic HART communication by writing / reading a
data record in conjunction with the data ready ID.
Steps
1
2
3
Fig. 4-6 The operating phase
Switch the programmable logic controller to
“RUN”: user data are transmitted cyclically via
PROFIBUS DP.
You can evaluate the user data cyclically
in your user program.
SIMATIC S7 HART Analog Modules
You can use the SIMATIC PDM parameter
assignment tool for diagnostic purposes and
modify the parameters of the field devices:
Start by double-clicking channel 0 (line 2) or
channel 1 (line 3) of the HART analog module,
depending on where the particular field device
is connected.
STEP7
SIMATIC
PDM
4-9