The basic operation of the TSX CTY 2A and 4A modules for counting or down counting only is explained below.
The counting or down counting operations are the changes of the same register of the module. The only difference is the direction of the change. This is defined by software configuration (counting or down counting only functions).
The changes of the counting register are possible only when the function is enabled:
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by a physical input (IVal ST_IENAB (%IWr.m.c.2.2)) with software pre-positioning (Enable command ENAB_IENAB (%Qr.m.c.5)),
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directly, using the software: Direct enable command DIR_ENAB (%Qr.m.c.0).
The count values vary between:
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0 and +16 777 215 for counting (24 bits with no sign),
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-16 777 216 and +16 777 215 for down counting (24 bits + sign).
This timing diagram shows the counting process. The down counting function is similar, but the change direction of the current value is reversed. The associated language objects are described in the
implicit objects part.
