
Functions
5.11 Operation in fieldbus systems
Frequency inverter
190
Operating Instructions, 08.10. 2008, t.b.d.
5.11.2.6
STEP 7 program examples
STEP 7 program example for cyclic communication
S7 program for controlling the frequency inverter
The S7 program, which supplies data for cyclic communication between the frequency
converter and the central controller, can be used for PROFIBUS and PROFINET.
In the example provided below, communication between the controller and frequency
converter is handled via standard message frame 1. The control specifies control word 1
(STW1) and the speed setpoint, while the frequency inverter responds with status word 1
(ZSW1) and its actual speed value.
Figure 5-35 Controlling the G120 via PROFIBUS or PROFINET