Stages (S Data Type); Special Relays (Sp Data Type); Remote I/O Points (Gx Data Type) - Automationdirect.com DirectLOGIC DL205 Series User Manual

Chapter 3: CPU Specifications and Operations

Stages (S Data type)

1
Stages are used in RLL
structured program, similar to a flowchart. Each
program stage denotes a program segment. When
2
the program segment, or stage, is active, the logic
within that segment is executed. If the stage is off,
3
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
4
programming.)
Each stage also has a discrete status bit that can be
5
used as an input to indicate whether the stage is
active or inactive. If the stage is active, then the
6
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
7
RESET instructions. This allows you to easily
control stages throughout the program.
8

Special Relays (SP Data Type)

Special relays are discrete memory locations with
9
pre-defined functionality. There are many different
types of special relays. For example, some aid in
10
program development, others provide system
operating status information, etc. Appendix D
provides a complete listing of the special relays.
11
In this example, control relay C10 will energize for
50 ms and de–energize for 50 ms because SP5 is a
12
pre–defined relay that will be on for 50 ms and off
for 50 ms.
13

Remote I/O Points (GX Data Type)

Remote I/O points are represented by global relays.
14
They are generally used only to control remote
I/O, but they can be used as normal control relays
when remote I/O is not used in the system.
A
In this example, memory location GX0 represents
an output point and memory location GX10
B
represents an input point.
C
D
3–40
DL205 User Manual, 4th Edition, Rev. B
PLUS programs to create a
PLUS
ISG
Wait forStart
S0000
Start
X0
SG
Check for a Part
S0001
Part
Present
X1
Part
Present
X1
SG
Clamp the part
S0002
Part
Locked
X2
SP5
SP4: 1 second clock
SP5: 100 ms clock
SP6: 50 ms clock
X3
GX10
S1
JMP
S500
JMP
S2
JMP
S6
JMP
Clamp
SET
S400
S3
JMP
C10
OUT
GX0
OUT
Y12
OUT