Siemens SIMATIC S5 Manual page 227

Sample Applications and Programming Aids
13.2 Programming Aids
This section discusses a number of programming aids for the IP 265 user program.
Programming aids (also called software tools) are program fragments containing complex functions
which must often be included in control programs for high-speed processes and which can be easily
linked into the IP 265 user program.
You will find programming aids for the following examples:
• Pulse evaluator for position decoder
- 1-fold pulse evaluation
- 2-fold pulse evaluation
• High-speed, reproducible resetting of an output
Example: Pulse evaluator for position decoder
An incremental position decoder supplies two in-quadrature pulse signals displaced by 90°. The
frequency of the pulse signal may not exceed 29 kHz.
A
B
Signal A leading
90°
The reference point is determined by a SYNCH signal at the counter's Reset input.
Signals A, B and SYNCH can be routed to both the 24 V inputs and the 5 V differential inputs
(RS422).
13-14
The position encoder's
sense of rotation changes
at this point
Figure 13-7. Sensor Signal Evaluation
Signal B leading
EWA 4NEB 812 6130-02a
IP 265
t