Operating instructions

Operating a project
8.2 Direct keys
MP 377, MP 377 PRO (WinCC flexible)
192 Operating Instructions, 10/2008, 6AV6691-1DR01-0AB0
8.2 Direct keys
Introduction
Direct keys on the HMI device are used to set bits in the I/O area of a SIMATIC S7.
Direct keys enable operations with short reaction times that are, for example,
a jog mode requirement.
NOTICE
Direct keys are still active when the HMI device is in "offline" mode.
NOTICE
If you operate a function key with direct key functionality in a running project, the direct key
function is always executed, independent of the current screen contents.
Note
You can only use direct keys when there is a connection via PROFIBUS DP or
PROFINET IO.
Direct keys result in additional basic load on the HMI device.
Direct keys
The following objects can be configured as a direct key:
● Buttons
● Function keys
You can also define image numbers in the case of HMI devices with touch operation. In this
way, the project engineer can configure the direct keys on an image-specific basis.
Further information on configuring direct keys can be found in the
"WinCC flexible Communication" system manual.