EUCHNER HBLS 072725 - Handbuch (Seite 35)

EUCHNER Pendant station HBLS 072725
067018-08-01/06 Subject to technical modifications page 13 / 22
9. Priorities at data collision (PLC has higher priority)
The PLC transmitter has a higher priority, and the HBLS transmitter has a lower priority.
In case of a collision, which means the HBLS recognises an incoming STX character from
the PLC while sending its own STX to the PLC at the same time, the data, intended to
transfer to the PLC will be interrupted and the data from the PLC will be handled first. When
completed, the data transfer from the HBLS to the PLC will be repeated.
Example of possible collisions:
HBLS is sending push button changed
STX DLE ??
PLC is sending “LED 1 ON” STX DLE ??
Solution:
HBLS is sending push button changed
STX DLE DLE STX
PLC is sending “LED 1 ON” STX 31H DLE ETX BCC