192
Enhanced Protocol Macro Functions
Section 5-6
Therefore, when a send command is executed in a step, the send message is
compiled immediately based on data read from the Board/Unit, and the actual
message is sent. Therefore, the actual message transmission is performed
immediately when the send command is executed (there is no need to wait
until the next I/O refresh with the CPU Unit). The receive command operation
is similar. When the receive data is stored in the Board/Unit, receive com-
mand execution is completed. The actual received data is stored in I/O mem-
ory at the next I/O refresh with the CPU Unit.
•
Setup Area Allocated in the DM Area
m = 100
×
unit number
Note
When “continuous I/O refreshing” is specified for the link word specification
data exchange timing, the normal I/O refresh will be executed with the CPU
Unit while protocol macros are being executed without syncing with execution
of the send and receive commands. You must therefore be careful of the data
exchange timing at the start and end of protocol macros.
1.
The new data may not be sent by the send command in a protocol macro
that is executed immediately after the send data in memory in the CPU Unit
is updated. The send data must be read to the SCU/SCB in the I/O refresh
period before it will be sent by the send command.
2.
Data received by a receive command in a protocol macro may not be re-
freshed in the CPU Unit if execution of the protocol macro is completed im-
mediately after the receive command. If the protocol macro is still being
executed during the I/O refresh period after the data is received by the re-
ceive command, the receive data will be refreshed in memory in the CPU
Unit.
The “continuous I/O refreshing” setting is suitable for applications in which
send/receive commands are executed repeatedly in the same protocol macro
(i.e., the same PMCR). If data in the CPU Unit is to be sent with a send com-
mand in the next protocol macro or receive data for a receive command is to
be refreshed in the CPU Unit and then the protocol macro ended, use the “on-
request I/O refreshing” setting.
Words
Bit
Setting
Board
Unit
Port 1
Port 2
Port 1
Port 2
D32008
D32018
m+8
m+18
02
Link word specification data
exchange timing
0: On-request I/O refreshing
1: Continuous I/O refreshing
PMCR
CPU Unit
Ladder program
I/O memory
Receive data
Send data
Board/Unit
Step 0
Step 1 (send)
(2)
(1)
Ex
ecution
instr
uction
IN
OUT
Receive data
Send data
I1
O1
Read, compile message
(3) Send
R (O1, 2)
Link word 1
Communications
sequence
(1) to (4) are performed in
order for the processing
within this dotted line.
Send message according
to send command
The refresh timing continuously refreshes I/O regardless of
the any request from the Board/Unit (using send/receive
commands in the communications sequence).
Summary of Contents for SYSMAC CJ1W-SCU21-V1
Page 3: ...iv...
Page 5: ...vi...
Page 9: ...x...
Page 15: ...xvi...
Page 89: ...60 Basic Operating Procedure Section 1 9...
Page 151: ...122 RS 232C and RS 422A 485 Wiring Section 3 4...
Page 173: ...144 Host Link Function for Replacing Existing PLCs Section 4 6...
Page 223: ...194 Enhanced Protocol Macro Functions Section 5 6...
Page 277: ...248 Communications Frames Section 6 8...
Page 291: ...262 Basic Operating Procedure in No protocol Mode Section 7 4...
Page 301: ...272 Auxiliary Area and CIO Area Allocations Section 8 3...
Page 391: ...362 Introduction Appendix A...
Page 421: ...392 CompoWay F Master Protocol Appendix B...
Page 513: ...484 E5 K Digital Controller Read Protocol Appendix F...
Page 571: ...542 E5ZE Temperature Controller Write Protocol Appendix I...
Page 587: ...558 E5 J Temperature Controller Protocol Appendix J...
Page 627: ...598 ES100 Digital Controller Protocol Appendix K...
Page 661: ...632 V500 V520 Bar Code Reader Protocol Appendix M...
Page 697: ...668 3Z4L Laser Micrometer Protocol Appendix N...
Page 717: ...688 Visual Inspection System Protocol Appendix O...
Page 755: ...726 V600 V620 ID Controller Protocol Appendix P...
Page 763: ...734 Hayes Modem AT Command Protocol Appendix Q...
Page 767: ...738 Changing Communications Port Settings Using STUP 237 Appendix R...
Page 781: ...752 Revision History...