Standard functions of the TSX CTY ••
3.8
Description of the speed measuring function for the TSX CTY 2C module
Speed Monitoring Function (TSX CTY 2C)
At a Glance
Operation
Speed monitoring, via user adjustable overspeed monitoring, provides a safety measure for the output(s) during an overspeed monitoring overshoot (the outputs are then set to 0). These outputs must be configured in automatic mode.
The figure below shows reflex output changes according to configuration (Q0 output example).
Speed
Overspeed monitoring
Faults Latch
Overspeed error
End of the fault Fault acknowledgement
Position or time
If the faults latch is configured:
Q0 output automatic mode
If the faults latch is not configured:
Q0 output automatic mode
When the output is in automatic mode: z if the faults latch is configured: when the fault has disappeared, it must be acknowledged in order to set the output to its initial state before the fault. A z premature acknowledgement has no effect.
if the faults latch is not configured: when the overspeed error disappears, the output is reset to its initial state.
92
35015371 00 May 2007
Standard functions of the TSX CTY ••
Note: outputs in manual mode
The outputs in manual mode are reset to zero by the overspeed error.
Choice of the
Measurement
Period
The default measurement period is 1 second, which can cause an excessive delay in the detection of overspeed, or an insufficient precision. It is possible to program the measurement period according to the speed to be monitored and the required precision:
Measurement period
1
precision x speed
where the precision is expressed as a decimal value (for example: 0.1% = 0.001) and the speed in pulses/second. The sampling period is expressed in seconds.
Admissible values range from 10
-2
s to 30 s.
The following table shows the minimum measurement period as a function of the speed to be measured, in order to ensure for example a precision of 0.1%.
Speed to be measured
(pulses/second)
250000 ... 1000000
40000 ... 250000
10000 ... 40000
1000 ... 10000
100 ... 1000
Minimum measurement period
(s)
Greater than or equal to 10
-2
Greater than or equal to 25 10
-3
Greater than or equal to 0.1
Greater than or equal to 1
Greater than or equal to 10
Precision
(%)
0.1
0.1
0.1
0.1
0.1
35015371 00 May 2007 93
