I/O Modules (840Di); External Smoothing Filters - Siemens SINUMERIK 840D sl Function Manual

11.9.1.2

I/O modules (840Di)

On the SINUMERIK 840Di, the analog I/O module is connected via PROFIBUS-DP.
Figure 11-15 Clearance sensor connection via analog S7 I/O module
Suitable I/O modules
As the A/D conversion time directly affects the deadtime of the clearance control servo loop,
only one I/O module may be used with low conversion time.
A SIMATIC S7 module suitable for clearance control is:
• Analog I/O module 2 AI, U, high-speed for ET 200S
Conversion time per channel (max. 2): 100 μs
Cycle time for both channels: 1 ms
Order number (MLFB): 6ES7 134-4FB50-0AB0
I/O module connection
A description of how the I/O modules are connected appears in:
References:
/HBi/ SINUMERIK 840Di Manual, PROFIBIUS-DP Communication, SIMATIC S7 I/O units
section
11.9.1.3

External smoothing filters

If an external filter is to be interconnected to smooth the output voltage of the clearance
sensor before the A/D conversion of the output voltage by the I/O module, please ensure that
the resulting time constant is small in relation to the NC position controller cycle.
Note
It is better for the control if electromagnetic shielding is used to ensure a large signal-noise
ratio than if smoothing filters are used in the signal path.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
TE1: Clearance control
11.9 Boundary conditions
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