S5-115F Manual
Addressing
5.3.2
Accessing the PIQ
New signal states are entered in the PIQ during program scanning. At the end of each program
scan, the PIQs are exchanged between the two subunits, compared, and transferred to the output
modules only if they are identical.
0
15
Writing bit by bit
for binary operations:
=Q 4.6
7 6 5 4 3 2 1 0
Bit No.
PIQ
Byte 4
Writing byte by byte
for transfer from ACCUM 1:
T QB 36
a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a
Byte 36
Writing word by word
for transfer from ACCUM 1:
T QW 52
a a a
a a a
a a a
a a a
High byte
ACCUM 1
Low byte
0
15
Byte 52
Byte 53
High byte
ACCUM 1
Low byte
Figure 5-7. Accessing the PIQ
EWA 4NEB 811 6148-02
5-7
