USB & RS232 Communication
Data Link Layer
EPOS4 Communication Guide
2-12
CCMC | 2019-11 | rel8759
2.2
Data Link Layer
2.2.1
Flow Control
The EPOS4 always communicates as a slave.
A frame is only sent as an answer to a request. All commands send an answer. The master must always ini-
tiate communication by sending a packet structure.
The data flow while transmitting and receiving frames are as follows:
Figure 2-2
USB/RS232 communication – Commands
Figure 2-3
USB/RS232 communication – Sending a data frame to EPOS4
Figure 2-4
USB/RS232 communication – Receiving a response data frame from EPOS4
