WAGO I/O-SYSTEM 750 Manual page 43

2.1.1.8.1.4 Up-to-Dateness of the Process Image
WAGO master and WAGO slave regularly send their current process image
independently of changes. If one party, (master or slave) no longer receives a
new process image, the most recently received data remains current. If the
master receives no new process image from a WAGO slave over a longer pe-
riod of time, it signals this in its status byte (in the real-time profile, see Sec-
tion 2.1.1.8.1.1).
The master also sends a current process image to external devices; however,
the updating of received data is not tested. There is no signaling in the status
byte as with WAGO devices. The recency of the data from external devices is
therefore not certain.
2.1.1.8.1.5 Aging Due to break off of Connection
If a connection ends, regardless of whether intended (by the command "Un-
bindRemoteDevice", see Appendix 6.3.5.29) or by the failure of the remote
device, the slot configured for this device is retained. The last transmitted data
remain in this slot until the connection is re-established.
In WAGO devices, the failure of a connection is signaled by LEDs and the
status byte. In the case of an intended cutoff of the connection, obsolete data is
not signaled as an error. When the connection is re-established, the parts of the
process image configured for this slot are overwritten with current data re-
gardless of the previous status.
WAGO-I/O-SYSTEM 750
I/O Modules
I/O Modules • 43
Special Modules