Library of Function Blocks
4.7
Function 05 - Digital Output (DO)
Operation
This block can perform a logic operation with inputs A and B. The output is sent to a two-position
selector switch. The other position is connected to input C. A high logic level at D, switches CH1 to
position "1", making the output equal to safety input C.
The logic operation to be performed by the block is defined by the parameter CLOG according to the
table 4.5.1:
INPUT OUTPUT
A B OR AND XOR NOR NAND NXOR
0 0 0 0 0 1 1 1
0 1 1 0 1 0 1 0
1 0 1 0 1 0 1 0
1 1 1 1 0 0 0 1
Table 4.5.1 - Truth table for digital
TYPE MNEM DESCRIPTION RANGE DEFAULT
I LIA Input A 0
I LIB Input B 0
I LIC Safety input C 0
I LID Input D to activate safety input
Addresses
0 to 170/225 to 240
0
I CLOG Logic function
0 - OR/1 - AND/2 - XOR
3 - NOR/4 - NAND/5 - NXOR
0
Number of Bytes per Type of Parameter: A = 0 C = 2 L = 8