WAGO-I/O-SYSTEM 750
Commissioning 93
750-325 CC-Link Fieldbus Coupler
Manual
Version 2.0.1
8.5.1
Initial Data Transfer Handshake
The initial data transfer handshake is run in the user program as follows:
Figure 41: Timing Diagram for the Initial Data Transfer Handshake
1.
If the power supply to the 750-325 fieldbus coupler is on, it first sets the
RX(m+n)8 flag (Initial data processing request) to ‘1’ to request the
initialization process from the master.
2.
The user program on the master returns a response via the RY(m+n)8 flag
(Initial data processing complete) by setting it to ‘1’.
3.
At the same time, the user program also sets the RY(m+n)9 flag (Initial data
setting request) on the master to ‘1’ to request data setting of the fieldbus
coupler for the initialization process.
4.
The fieldbus coupler sets the X(m+n)8 request flag (Initial data processing
request) back to ‘0’.
5.
It responds to the master's request in parallel by setting the RX(m+n)9 flag
(Initial data setting complete) to ‘1’.
6.
The user program on the master then sets the RY(m+n)8 flag (Initial data
processing complete) back to ‘0’.
7.
It then also sets the RY(m+n)9 flag (Initial data setting request) back to ‘0’.
8.
The fieldbus coupler also sets the RX(m+n)9 (Initial data setting complete)
back to ‘0’.
9.
By setting the RX(m+n)B flag (Remote station ready) to ‘1’, the fieldbus
then indicates that communication has been established.