Activation Of Function Key Leds Using System Functions - Siemens SIMATIC HMI Operating Instructions Manual

Operator controls and displays
5.5 Operator controls
● Number of pulses, forwards
● Number of pulses, backwards
From this, you determine the resulting value. This is calculated as:
–
–
+
=
Reaction time
The bytes "n+4" and "n+5" must be retrieved on the PLC side within a second and cyclically.
This ensures that no more than 256 pulses can be added between two scans of the
handwheel. For 256 pulses, approximately 4.5 revolutions of the handwheel are required.
The rotary pulse encoder supplies a maximum of 200 pulses per second.
NOTICE
Sample cycle time
The input pulses should take effect immediately on the PLC and cause a response in the
system. Set a scan cycle ≤ 100 ms in the PLC in order to achieve this.
See also
Direct keys (Page 234)
5.5.4.3

Activation of function key LEDs using system functions

Application
LEDs are integrated in the HMI device's function keys F1 to F18. The integrated LEDs can
be controlled from the PLC.
The LEDs can assume the following states:
● Off
● Flashing slowly
● Flashing quickly
110
– At time t
n
– At time t
n+1
– At time t
n
– At time t
n+1
Pulses, forwards, t
n+1
Pulses, forwards, t
n
Pulses, backwards, t
n+1
Pulses, backwards, t
n
Resulting value
Mobile Panel 277F IWLAN
Operating Instructions, 12/2007, A5E01003940-01