AutomationDirect DL105, User Manual

Page: 154 / 350

CPU
S
pecifications
and
Operation
4--25
CPU Specifications and Operation
DL105 PLC User Manual, 3rd Edition
Word memory is referred to as
V--memory (variable) and is a 16-bit
location normally used to manipulate
data/numbers, store data/numbers, etc.
(see Appendix E).
Some information is automatically stored
in V--memory. For example, the timer
current values are stored in V--memory.
The example shows how a four-digit
BCD constant is loaded into the
accumulator and then stored in a
V-memory location.
0 1 0 0 1 0 0 1 1 0 1 0 0 0 1 0
Word Locations -- 16 bits
X0
LD
K1345
OUT V2000
1 3 4 5
Stages are used in RLL
PLUS
Stage
programs to create a structured
program, similar to a flowchart. Each
program stage denotes a program
segment. When the program segment,
or stage, is active, the logic within that
segment is executed. If the stage is off, or
inactive, the logic is not executed and the
CPU skips to the next active stage. (See
Chapter 7 for a more detailed description
of RLL
PLUS
Stage programming.)
Each stage also has a discrete status bit
that can be used as an input to indicate
whether the stage is active or inactive. If
the stage is active, then the status bit is
on. If the stage is inactive, then the status
bit is off. This status bit can also be turned
on or off by other instructions, such as the
SET or RESET instructions. This allows
you to easily control stages throughout
the program.
Ladder Representation
ISG
S0000
Start S1
JMP
SG
S0001
Present
S2
JMP
Part
X1
X0
S6
JMP
Present
Part
X1
SG
S0002
Clamp
SET
S3
JMP
Locked
Part
X2
S400
Wait forStart
Check for a Part
Clamp the part
S500
JMP
Special relays are discrete memory
locations with pre-defined functionality.
There are many different types of special
relays. For example, some aid in
program development, others provide
system operating status information, etc.
Appendix D provides a complete listing of
the special relays.
In this example, control relay C10 will
energize for 50 ms and de-energize for
50 ms because SP5 is a pre--defined
relay that will be on for 50 ms and off for
50 ms.
C10
OUT
SP5
SP4: 1 second clock
SP5: 100 ms clock
SP6: 50 ms clock
Word Memory
(V Data Type)
Stages
(S Data type)
Special Relays
(SP Data Type)