Specifications

SIMATIC Instructions
9-52
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
Single Segment Pipelining In single segment pipelining, you are responsible for
updating the SM locations for the next pulse train. Once the initial PTO segment
has been started, you must modify immediately the SM locations as required for
the second waveform, and execute the PLS instruction again. The attributes of the
second pulse train will be held in a pipeline until the first pulse train is completed.
Only one entry at a time can be stored in the pipeline. Once the first pulse train is
completed, the output of the second waveform will begin and the pipeline is made
available for a new pulse train specification. You can then repeat this process to
set up the characteristics of the next pulse train.
Smooth transitions between pulse trains will occur except in the following
situations:
 If a change in time base is performed
 If the active pulse train is completed before a new pulse train setup is captured
by the execution of the PLS instruction.
If you attempt to load the pipeline while it is full, the PTO overflow bit in the status
register (SM66.6 or SM76.6) is set. This bit is initialized to zero on entry to RUN
mode. If you want to detect subsequent overflows, you must clear this bit manually
after an overflow is detected.
Multiple Segment Pipelining In multiple segment pipelining, the characteristics
of each pulse train segment are read automatically by the CPU from a profile table
located in V memory. The only SM locations used in this mode are the control byte
and the status byte. To select multiple segment operation, the starting V memory
offset of the profile table must be loaded (SMW168 or SMW178). The time base
can be specified to be either microseconds or milliseconds, but the selection
applies to all cycle time values in the profile table, and cannot be changed while
the profile is running. Multiple segment operation can then be started by executing
the PLS instruction.
Each segment entry is 8 bytes in length, and is composed of a 16-bit cycle time
value, a 16-bit cycle time delta value, and a 32-bit pulse count value.