UMDIO128CO V2.0.1 Preliminary Documentation – May be Subject to Change 8-53
1.4.
Digital Input Function Block
Figure 2 – Digital Input Objects
For the digital inputs (DI), all associated objects (except 2003h) are an 8-bit type. The table below
shows the relationship between each bit and the corresponding input.
Subindex Bit 7 Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1 Bit 0
1
DI8 DI7 DI6 DI5 DI4 DI3 DI2 DI1
2
- - - -
DI12 DI11 DI10
DI9
Table 2 – Digital Input Bitmap
In all cases when talking about bit data, the following relationships hold true:
0 = OFF
1 = ON
0 = FALSE
1 = TRUE
0 = DISABLED 1 = ENABLED
When evaluating a DI, the controller will read the level (0,1) at the pin, and when it detects a
change of state, it looks at object
6002h, DI Filter Input.
When filtering is ENABLED (default 1),
the level change at the input will not be passed to the rest of the function block until after the time
in
2003h, DI Debounce Time
(default 30ms) has elapsed, as shown in Figure 3. If and only if the
input is the same after debouncing will the state change be reflected in the “Input Level” logic. If
6002h is DISABLED, the “Input Level” immediately reflects the state of the pin.
Figure 3 – Digital Input Debouncing
