![background image](http://html1.mh-extra.com/html/omron/sysmac-cj1w-scu21-v1/sysmac-cj1w-scu21-v1_operation-manual_743586365.webp)
336
Troubleshooting
Section 11-3
Note
1.
The PT serial port must be set for a 1:N NT Link. The PT will not be able
to communicate with a Serial Communications Board or Unit if the PT is
set for a 1:1 NT Link.
2.
The System Setup cannot be changed unless the power supply is cycled,
the Board or Unit is restarted, the port is restarted, or the STUP(237) in-
struction is executed. Refer to
1-7 Comparison to Previous Products
for de-
tails.
Serial communi-
cations mode is
set to NT Link.
The SD
@
/RD
@
and COM
@
indi-
cators are flash-
ing, but a
communica-
tions error
sometimes
occurs in the PT.
---
---
Cables are incor-
rectly connected.
The RS-422A/485
port setting (2-wire
or 4-wire) is incor-
rect.
Adapters such as the
NT-AL001-E are
incorrectly wired or
set.
Review the wiring or switch
settings.
Check whether the termi-
nating resistances of the
host computer and the last
Unit are set to ON, and the
terminating resistances of
other Units are set to OFF.
A communications
error frequently
occurs due to noise,
etc.
Review the wiring and
installation environment.
Increase the number of
retries for the PT as
required.
The communica-
tions monitoring time
for the PT is insuffi-
cient.
Increase the communica-
tions monitoring time for the
PT.
The load on the PLC
is too high.
Lighten the load on the
PLC.
Reduce the number of PTs
connected to each serial
port by using other ports for
some of the PTs.
Adjust the timeout and retry
settings in the PT.
Serial commu-
nications mode
Indicator
display
Status
information,
etc.
Words allo-
cated in the
CIO Area
Cause
Remedy
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...