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370
Serial Communications
Section 6-3
Procedure
Message Frame Formats
Data can be placed between a start code and end code for transmission by
TXD(236) and data between a start code and end code can be received by
RXD(235). When transmitting with TXD(236), data from I/O memory is trans-
mitted, and when receiving with RXD(235), the data (without start/end codes)
is stored in I/O memory. Up to 256 bytes (including the start and end codes)
can be transferred in no-protocol mode.
The start and end codes are set in the PLC Setup.
The following table shows the message formats that can be set for transmis-
sions and receptions in no-protocol mode.
• When more than one start code is used, the first start code will be effec-
tive.
• When more than one end code is used, the first end code will be effective.
• If the data being transferred contains the end code, the data transfer will
be stopped midway. In this case, change the end code to CR+LF.
Set the PLC Setup from the CX-
Programmer.
(Set the communications mode to
RS-232C
and set the parameters.)
Power OFF
Connect the CPU Unit and external device through
RS-232C or RS-485. (Mounting the RS-232C or
RS-422A/485 Option Board in option slot 1 or 2.
Set the DIP switch on the front of
the CPU Unit.
Turn OFF pin 4 to use serial port 1.
Turn OFF pin 5 to use serial port 2.
Note
Serial port 2 is not supported by CPU
Units with 20/14 I/O points.
Serial port 1 and 2 are not supported
by CPU Units with 10 I/O points.
Power ON
PLC
→
External device
External device
→
PLC
Execute TXD(236).
Execute RXD(235).
Start code
End code
No
Yes
CR+LF
No
Yes
data
256 bytes max.
data
256 bytes max.
ED
data
256 bytes max.
CR+F
data
256 bytes max.
ST
data
256 bytes max.
ST
ED
data
256 bytes max.
ST
CR+LF
Summary of Contents for CP1L CPU UNIT - 03-2009
Page 1: ...Cat No W462 E1 06 CP1L CPU Unit SYSMAC CP Series CP1L L_0D_ CP1L M_0D_ OPERATION MANUAL...
Page 2: ......
Page 4: ...iv...
Page 10: ...x...
Page 22: ...xxii...
Page 34: ...xxxiv Conformance to EC Directives 6...
Page 70: ...36 Function Blocks Section 1 5...
Page 584: ...550 Trouble Shooting Section 8 7...
Page 627: ...593 Sample Application Section 9 12 Network Settings Network Tab Network Settings Driver Tab...
Page 630: ...596 Sample Application Section 9 12...
Page 654: ...620 Troubleshooting Unit Errors Section 11 4...
Page 662: ...628 Replacing User serviceable Parts Section 12 2...
Page 668: ...634 Standard Models Appendix A...
Page 698: ...664 Auxiliary Area Allocations by Function Appendix C...
Page 746: ...712 Auxiliary Area Allocations by Address Appendix D...
Page 773: ...739 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 774: ...740 Connections to Serial Communications Option Boards Appendix F...
Page 806: ...772 Index...
Page 808: ...774 Revision History...