Profile Table Values - Siemens SIMATIC S7-200 System Manual

Assuming that the profile table is located in V memory starting at V500, the table
values used to generate the desired waveform are shown in Table 9-16.
Table 9-16 Profile Table Values
V Memory Address
VB500
VW501
VW503
VD505
VW509
VW511
VD513
VW517
VW519
VD521
The values of this table can be placed in V memory by using instructions in your
program. An alternate method is to define the values of the profile in the data
block. An example containing the program instructions to use the multiple segment
PTO operation is shown in Figure 9-23.
The cycle time of the last pulse of a segment is not directly specified in the profile,
but instead must be calculated (except of course for the case in which the delta
cycle time is zero). Knowing the cycle time of a segment's last pulse is useful to
determine if the transitions between waveform segments are acceptable. The
formula for calculating the cycle time of a segment's last pulse is shown below:
cycle time of segment's last pulse = ICT + ( DEL * ( Q-1 ))
where, ICT = initial cycle time for this segment
DEL = delta cycle time for this segment
Q
While the simplified example above is useful as an introduction, real applications
may require more complicated waveform profiles. Remember that:
The delta cycle time can be specified only as an integer number of
microseconds or milliseconds
The cycle time modification is performed on each pulse
The effect of these two items is that calculation of the delta cycle time value for a
given segment may require an iterative approach. Some flexibility in the value of
the ending cycle time or the number of pulses for a given segment may be
required.
S7-200 Programmable Controller System Manual
A5E00066097-02
3 (total number of segments)
500 (initial cycle time - segment #1)
-2 (initial cycle time - segment #1)
200 (number of pulses - segment #1)
100 (initial cycle time - segment #2)
0 (delta cycle time - segment #2)
3400 (number of pulses - segment #2)
100 (initial cycle time - segment #3)
1 (delta cycle time - segment #3)
400 (number of pulses - segment #3)
= quantity of pulses in this segment
SIMATIC Instructions
Value
9-55