User Manual

206 Rockwell Automation Publication 1752-UM001E-EN-P - June 2014
Appendix C Logic Functions Command Reference
OR Instruction
The Output is the logical OR of up to eight input conditions. The number of
inputs can be set by using the In/Out Setting tab in the Function Block
Properties dialog box. The default setting is two inputs.
OR Instruction Diagram
OR Instruction Truth Tables
In the truth table, 0 is off and 1 is on. Lowercase x is don’t care.
Table 41 - Truth Table for Eight-input AND Evaluation
Input 1 Input 2 Input 3 Input 4 Input 5 Input 6 Input 7 Input 8 Output 1
0xxxxxxx 0
x0xxxxxx 0
xx0xxxxx 0
xxx0xxxx 0
xxxx0xxx 0
xxxxx0xx 0
xxxxxx0x 0
xxxxxxx0 0
11111111 1
Table 42 - Truth Table for One-input OR Evaluation
Input 1 Output 1
00
11
Table 43 - Truth Table for Two-input OR Evaluation
Input 1 Input 2 Output 1
000
1x1
x11
Output 1Input 1
Input 2