Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE - Manual (Page 127)

ASCII I/O Module Tutorial
Chapter 4
4Ć53
Figure 3.10
Binary and BCD Interpretation of 10110
Binary
Place Value
128 64 32 16 8 4 2 1
1 0 1 1 0
BCD
Place Value
80 40 20 10 8 4 2 1
1 0 1 1 0
16 + 4 + 2 = 22 10 + 4 + 2 = 16
NOTE: To obtain the value in either base, add the place values wherever a 1 appears.
11838
1. Observe the difference between binary and BCD representation of an
accumulated value (free running timer) in rungs RM19 and RM20 of
your program.
Output word R WO009:0007(rung RM20) shows binary
Output word R WO006:0007(rung RM19) shows BCD
2. Enable input bit I0001/04 and compare the binary and BCD values
that are displayed just below output word R in the instruction.
Procedure P3 Connect the 1775ĆCAT cable, and set the industrial terminal
to PLCĆ3 mode
Procedure P6 Enable bit I001/04. With the PLCĆ3 in run monitor, enter the
bit and enable it
Results Binary and BCD representation of selected accumulated values
are tabulated in Table 3.Q.
Table 3.Q
Comparison of Binary and BCD Interpretation of the Same Bit Pattern
Accumulated
Value
WO009:0007
Binary
WO006:0007
BCD
1
9
10
20
30
40
50
1
1001
1010
10100
11110
101000
110010
1
1001
1000
100000
110000
1000000
1010000