Understanding Module Operation
3-5
High Speed Counter Encoder Module User Manual
Each 24-bit counter has two preset values to control two outputs, as listed in
Table 3-1 and shown in Figure 3-1. The 24-bit unipolar value for each preset
is contained in the lower byte of the most significant word and both bytes of
the least significant word, as shown by the shaded areas in Table 3-3. The
upper byte of the most significant word is used to configure the counters
and outputs.
Table 3-3
24-Bit Preset Value Format
Word
MSByte
LSByte
MSWord
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
LSWord
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
The current count value for each 16-bit counter is contained in a one word
input, (for example, WX3 for Counter 2). The preset value for each 16-bit
counter uses a single word output, (for example, WY25 for Counter 2). The
format for the count value and preset value is shown in Table 3-4.
Table 3-4
16-Bit Value Format
Word
MSByte
LSByte
WX/WY
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
•
The count range is from 0 to 65535 (2
16
) in integer format.
•
The count range is from –32768 to +32767 (2
16
) in signed integer
format.
•
Overflow and underflow occur at about the 0 value.
The module handles all values and presets as unipolar format. You can
choose to handle the values in either integer or signed integer format.
24-Bit Preset and
Configuration
Formats
16-Bit Count and
Preset Value
Formats
