1 noise filter, 5 reset state, 2 connectors j2/j3 – Sensoray 826 User Manual
Page 55: 3 programming, Noise filter, Reset state, Connectors j2/j3, Programming
8.1.4.1
Noise Filter
Each DIO channel input circuit includes a noise filter that can be used to filter glitches (see S826_DioFilterWrite). A filter's
output will change state only when its input has held constant for time T, the filter time interval. Consequently, when a DIO
channel's filter is enabled, the sampled input signal will be delayed for an additional T * 20 ns en route to its destination,
and input signal pulses shorter than T * 20 ns will not be recognized.
8.1.5 Reset State
DIO channels are forced to the following condition upon board reset:
•
Output and Safe Data registers programmed to zero.
•
Safe Enable registers programmed to all 1's.
•
Output register is selected as I/O pin data source.
•
Event capture disabled.
8.2 Connectors J2/J3
J2 Pinout - DIO channels 24-47
Pin
1
3
5
7
9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47
49
Even
DIO Channel
47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 30 30 29 28 27 26 25 24 +5V
GND
J3 Pinout - DIO channels 0-23
Pin
1
3
5
7
9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47
49
Even
DIO Channel
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
+5V
GND
All even pin numbers on J2 and J3 connect to the power supply return. Odd pin numbers 1-47 are the active-low DIO
channel I/O pins. Pin 49 is a +5V power output for low power loads such as solid state relay racks.
8.3 Programming
The DIO functions use individual bits to convey information about the DIO channels, wherein each bit represents the
information for one channel. In such cases, the information for the 48 DIO channels is organized as an array of two bit
quadlets (32-bit values), with each quadlet containing the information for 24 DIO channels:
The quadlet at array[0] is associated with DIO channels 0 to 23:
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
DIO
-
-
-
-
-
-
-
-
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
The quadlet at array[1] is associated with DIO channels 24 to 47:
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
DIO
-
-
-
-
-
-
-
-
47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24
Typically, the DIO functions expect a pointer to a two-quadlet array, which must have been previously allocated by the
program.
826 Instruction Manual
50
Digital I/O