Programming Precautions - YASKAWA MP920 User Manual

7 218IF Module

7.7.5 Programming Precautions

7.7.5
MEMOBUS Response Data
• Copy the identification number set in the MEMOBUS command data.
• Copy the leading source channel number set in the MEMOBUS command data is copied
as the leading destination channel.
• A unique Machine Controller value is added for the source channel. It can therefore be
ignored at the personal computer.
• Reverse the upper 4 bits and the lower 4 bits of the CPU numbers in the MEMOBUS
command data and set is as the CPU numbers. If it is not required at the personal com-
puter, it can be ignored.
Using the Personal Computer as a Slave
MEMOBUS Response Data
• Set the number that is set in the MEMOBUS command data for the identification num-
ber.
• Set the source channel number in the MEMOBUS command data for the destination
channel.
• Set the destination channel number in the MEMOBUS command data for the source
channel.
• Reverse the upper 4 bits and the lower 4 bits of the CPU numbers in the MEMOBUS
command data and set is as the CPU numbers.
Sample Program
Appendix C C Language Sample Programs shows a sample program for the personal com-
puter.

Programming Precautions

When a Master program is created with TCP, its own IP address or port number may not
always be allocated by the bind ( ) function. This depends on the application. In this case, the
system will automatically allocate an unused port number when the connect ( ) function is
called.
When the DST. IP Address and the DST. Port are set in the Transmission Parameters Tab
on the CP-218 Connection Parameter Window, the connection will be rejected if the IP
address and the port number do not match. Use the method shown below to avoid this situa-
tion.
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