Chapter 5
Theory of Operation and Register-Level Programming
5-10
©
National Instruments Corporation
Scanning Order
The order in which channels are scanned depends on the contents of the
mux-gain memory. The mux-gain memory on the MIO board can be loaded
with a sequence to scan the MIO onboard channels in any order. Figure 5-5
shows the scanning order on the AMUX-64T. Table 5-3 shows the order in
which the AMUX-64T channels are scanned for every MIO board input
channel for different AMUX-64T configurations. Observe that channels 0
through 15 of the MIO board are used for a single-ended input
configuration, but only channels 0 through 7 are used for a differential
input configuration.
Table 5-3.
AMUX-64T Scanning Order for Each MIO Board Input Channel
MIO Board
AMUX-64T Channels
One Board
Two Boards
Four Boards
Board A
Board A
Board B
Board A
Board B
Board C
Board D
0
0–3
0–3
64–67
0–3
64–67
128–131
192–195
1
4–7
4–7
68–71
4–7
68–71
132–135
196–199
2
8–11
8–11
72–75
8–11
72–75
136–139
200–203
3
12–15
12–15
76–79
12–15
76–79
140–143
204–207
4
16–19
16–19
80–83
16–19
80–83
144–147
208–211
5
20–23
20–23
84–87
20–23
84–87
148–151
212–215
6
24–27
24–27
88–91
24–27
88–91
152–155
216–219
7
28–31
28–31
92–95
28–31
92–95
156–159
220–223
8
32–35
32–35
96–99
32–35
96–99
160–163
224–227
9
36–39
36–39
100–103
36–39
100–103
164–167
228–231
10
40–43
40–43
104–107
40–43
104–107
168–171
232–235
11
44–47
44–47
108–111
44–47
108–111
172–175
236–239
12
48–51
48–51
112–115
48–51
112–115
176–179
240–243
13
52–55
52–55
116–119
52–55
116–119
180–183
244–247
14
56–59
56–59
120–123
56–59
120–123
184–187
248–251
15
60–63
60–63
124–127
60–63
124–127
188–191
252–255