Except for the single capture modes, described in the previous paragraph, module TSX CTY 2C has two specific modes:
-
capture of rising edges and falling edges of the input ICapt. This is an extension to the single capture principle, described in the previous Section.
-
capture combined at hardware preset (capture before preset mode).
Capture mode on rising and falling edges
The capture mode on rising edges and falling edges of the ICapt physical input can be used, for example, to measure the lengths of parts. This depends on an exterior pulse for two successive captures to be carried out.
The allowable interval between the two capture fronts must be a minimum of 0.5 ms. This is therefore the minimum size of the capture pulse.
Respecting this condition guarantees the correct running of the function, i.e. taking into account of all the edges present on the physical capture input.
The table below gives as an example this interval according to counting input frequency.
|
Counting input frequency
|
Minimum interval between capture edges (in number of counting pulses)
|
|
125 kHz
|
63
|
|
250 kHz
|
125
|
|
500 kHz
|
250
|
|
1 MHz
|
500
|
Capture before preset mode
This capture mode, specific to module TSX CTY 2C, applies to the up/down counting of pulses (proximity detector, incremental encoder), but not to the acquisition of data from the absolute encoder
The preset IPres physical input triggers successively:
-
a capture,
-
followed by the preset.
