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239
Communications Frames
Section 6-8
Response Frame
6-8-3
Modbus-ASCII
Command Frame
Frame before Conversion
FINS header
Modbus-RTU frame
Start (silent
interval of
3.5
characters)
(See note.)
End (silent
interval of
3.5
characters)
(See note.)
Slave
address
(1 byte)
FINS command
FUNCTION
code
(1 byte)
Communications data
(n bytes)
Error
check
CRC
(1 byte)
FINS end code
Frame after Conversion
Modbus-RTU
(command section only)
FUNCTION
code (1 byte)
Slave
address
(1 byte)
SRES
MRES
SRC
Remote
network
address
(DNA)
Remote
node
address
(DA1)
Remote
unit
address
(DA2)
MRC
04
Serial port
allocated
address
00 hex
Serial
port
unit
address
28
or local
network
address
or local
network
node
address
Etc.
User-
speci-
fied
User-
speci-
fied
Communica-
tions data
(n bytes)
Frame before Conversion
FINS header
FINS command
Remote
network
address
(DNA)
Remote
node
address
(DA1)
Remote
unit
address
(DA2)
MRC
Serial port
allocated
address
00 hex
Serial
port
unit
address
or local
network
address
28
05
or local
network
node
address
Modbus-ASCII
(command section only)
Slave
address
(ASCII code
2 characters:
2 bytes)
FUNCTION
code
(ASCII code
2 characters:
2 bytes)
Communications data
(ASCII code n characters)
Header
":"
(ASCII code
3A hex)
FUNCTION code
(ASCII code
2 characters:
2 bytes)
CR
(0D hex)
Modbus-ASCII frame
Communications data
(ASCII code n characters)
LF
(0A hex)
Slave address
(ASCII code
2 characters:
2 bytes)
Frame after Conversion
SRC
Etc.
LRC
(2 ASCII
characters:
2 bytes)
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...