FD67 Profibus-DP Manual
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8.3 Analogue I/O modules
8.3.1 Specific characteristics
8.3.1.1 Smoothing (Analogue input modules only)
The analogue signal can be prefiltered in the device, e.g. to reduce sensitivity to short-time measurement
variations.
Measurement time per channel is 2,0 ms. The total time of a cycle results from the measurement time per
c 2,5 ms. The graph below shows the module behaviour to the response time in an active
channel.
Response time on filtered active channel
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
1,1
0
250
500
750
1000
1250
1500
1750
2000
Time [ms]
Mesured size
Strong
Medium
Weak
♦
Fig. 8-1 : Time-dependent behaviour of smoothing in FD67 analogue input modules
8.3.1.2 Delta (Analogue input modules only)
This value sets the number of increments to increase or reduce the last measured value, in order to send
the analogue input value from the module to the bus node. This parameter can be used to reduce the bus
load of the internal system connection.
Example : The last measured value was 1000. With a delta of 100, the next measured value will only be
sent, if it is < 900 or > 1100.