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5
Simatic 505 SoftShop
the counts-per-step values are stored as 16 consecutive 16-bit words in
DCP-Memory (except for the DRUM). For the DRUM instruction,
counts-per-step values are stored in L-Memory; DCP is not used.
NOTE
If you use an operator interface to change the drum preset values
(DSP or DCP), the new values are not changed in the original RLL
program. If the RLL presets are ever downloaded, e.g., as the result of a
complete restart or an edit of the network containing the drum instruction,
the changes made with the operator interface are replaced by the values in
the RLL program.
When the instruction is actually operating, the current step is stored as a
16-bit word in DSC-Memory. The current count for this step is stored as
a 16-bit word in DCC-Memory.
PGTS Discrete Parameter Area
The Parameter Go To Subroutine (PGTS) discrete parameter area (Figure
5.3) is an area of memory within the controller that is reserved for
holding the status of discrete bits referenced as parameters in a PGTS
RLL instruction. Because up to 32 PGTS subroutines can be
programmed, the controller has 32 discrete parameter areas, each capable
of storing the status for 20 discrete parameters. When you use a
parameter in the subroutine, refer to discrete points as Bn where n = the
parameter number.
1
2
3
4
5
6
15
16
17
18
19
20
Discrete inputs
Discrete outputs
Control relays
PGTS discrete
parameter area
Values are copied into the
discrete parameter area to
be used by the subroutine.
When parameters are
specified read/write,
changed values are copied
back into appropriate
memory areas.
Figure 5.3
PGTS Word Parameter Area
The PGTS word parameter area (Figure 5.4) is an area of memory within
the controller that is reserved for holding the contents of 16-bit words
referenced as parameters in a PGTS RLL instruction. Because up to 32
PGTS subroutines can be programmed, the controller has 32 word
parameter areas, each capable of storing the status for 20 word
parameters. When you use a parameter in the subroutine, refer to words
as Wn, where n = the parameter number.