Siemens Add 7 AddFEM Manual page 14

AddFEM
nal signal amplifier.
Both analog and digital outputs are resistant to short circuits. All the outputs are
monitored and can be connected in parallel with other outputs. The analog and di-
gital areas are isolated from each other.
Please also refer to Chapter 4 for further technical data of the inputs and outputs.
Increasing the Availability through Redundancy
Redundancy in this context means the implementation of a "1–of–2" structure,
whereby the availability is increased by the parallel use of two AddFEM units. If an
AddFEM fails due to a fault, the second AddFEM takes over the function. In the
case of an AddFEM 6DL3100–8AA the redundancy is configured to the automation
processor. In the case of an AddFEM 6DL3100–8AB/–8AC the redundancy control
is implemented as a system utility of the AddFEM. To this purpose a redundancy
coupling via optical–fiber cable is used to transfer status and update information.
Extensive redundancy mechanisms and self–diagnostic functions which are inte-
grated in the AddFEM ensure automatic error recognition and changeover without
any manual interventions being required.
Redundancy of PROFIBUS DP Connection
The AddFEM has two PROFIBUS DP interfaces (DP A and DP B) which operate
in parallel. This allows redundant system structures to be implemented. As a rule
the process input information is transferred in parallel via both PROFIBUS DP in-
terfaces. By contrast only the process output information of the DP interface which
is currently active is transferred to the output pins. The process output information
of the currently passive DP interface is analyzed for monitoring purposes. The ma-
ster–reserve status of the two DP interfaces, meaning which DP interface is active
with regard to the output information and which interface is passive, can be speci-
fied by the automation processor.
Preprocessing Functions
The AddFEM offers the possibility of relocating automation subfunctions, such as
the positioner at turbine control systems, as preprocessing functions on the
AddFEM module. These preprocessing functions are called Front End Functions
(FEF).
GSD File
If the AddFEM is used with SIMATIC S7, the PROFIBUS DP parameters as well
as the properties of the AddFEM inputs and outputs (for example, measuring ran-
ges, filtering, etc.) are configurable by means of HW Config in the SIMATIC Mana-
ger. The corresponding settings are carried out by means of the COM–PROFIBUS
software package when used under SIMADYN D. In both cases the so–called
GSD file of the AddFEM has to be linked before configuration begins. The GSD file
describes the possibilities for setting the AddFEM and is called either
AddFEM
C79000–G8076–C900–03
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Area of Application
1-3