![background image](http://html1.mh-extra.com/html/omron/sysmac-cj1w-scu21-v1/sysmac-cj1w-scu21-v1_operation-manual_743586164.webp)
135
Communications Timing
Section 4-4
Command transmission to the host computer can start even when the port is
receiving a command from the host computer (1). The transmission of a
response to the command from the host computer is postponed until the
transmission of the command to the host computer is completed (2).
When a response is not required from the host computer, the Communica-
tions Port Enabled Flag will turn ON when the command to the host computer
has passed from the CPU Unit to the port.
Host Computer Receiving Data
At (1) in the diagram, the response to a command sent from the host com-
puter is being transmitted from the port. In this case, the command transmis-
sion to the host computer is postponed until the response transmission is
completed (2).
When a response is not required from the host computer, the Communica-
tions Port Enabled Flag will turn ON when the command to the host computer
has passed from the CPU Unit to the port.
Response Required
Host computer
Command
Command
Response
Response
Serial Communications
Board/Unit
Communications Port Enabled Flag
Command acknowledged
Command completed
No Response Required
Host computer
Serial Communications
Board/Unit
Command
Command
Response
Communications Port Enabled Flag
Command acknowledged
Command completed
(1)
(2)
(1)
(2)
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...