Automating Manufacturing Systems - Process Control and ...

plc memory - 14.10
15
0
B3:0
B3:1
B3:2
B3:3
B3:4
B3:5
B3:6
B3:7
This bit is B3:2/3
or B3/35.
(2) * 16 + (3) = (35)
Other Examples:
B3:0/0 = B3/0
B3:0/10 = B3/10
B3:1/0 = B3/16
B3:1/5 = B3/21
B3:2/0 = B3/32
etc...
Figure 14.12
Bit Memory
This method can also be used to access bits in integer memory also.
14.4.2 Timer Counter Memory
Previous chapters have discussed the operation of timers and counters. The ability
to address their memory directly allows some powerful tools. Recall that by default timers
are stored in the T4: file. The bits and words for timers are;
EN - timer enabled bit (bit 15)
TT - timer timing bit (bit 14)
DN - timer done bit (bit 13)
PRE - preset word
ACC - accumulated time word
Counter are stored in the C5: file and they have the following bits and words.