xxiii
Safety Precautions
3
!WARNING
Do not touch any of the terminals or terminal blocks while the power is being
supplied. Doing so may result in electric shock.
!WARNING
Do not attempt to disassemble, repair, or modify any Units. Any attempt to do
so may result in malfunction, fire, or electric shock.
!WARNING
Do not touch the Power Supply Unit while power is being supplied or immedi-
ately after power has been turned OFF. Doing so may result in electric shock.
!WARNING
Provide safety measures in external circuits (i.e., not in the Programmable
Controller), including the following items, to ensure safety in the system if an
abnormality occurs due to malfunction of the PLC or another external factor
affecting the PLC operation. Not doing so may result in serious accidents.
• Emergency stop circuits, interlock circuits, limit circuits, and similar safety
measures must be provided in external control circuits.
• The PLC will turn OFF all outputs when its self-diagnosis function detects
any error or when a severe failure alarm (FALS) instruction is executed.
As a countermeasure for such errors, external safety measures must be
provided to ensure safety in the system.
• The PLC outputs may remain ON or OFF due to deposition or burning of
the output relays or destruction of the output transistors. As a counter-
measure for such problems, external safety measures must be provided
to ensure safety in the system.
• When the 24-V DC output (service power supply to the PLC) is over-
loaded or short-circuited, the voltage may drop and result in the outputs
being turned OFF. As a countermeasure for such problems, external
safety measures must be provided to ensure safety in the system.
!Caution
Confirm safety before transferring data files stored in the file memory (Mem-
ory Card or EM file memory) to the I/O area (CIO) of the CPU Unit using a
peripheral tool. Otherwise, the devices connected to the output unit may mal-
function regardless of the operating mode of the CPU Unit.
!Caution
Fail-safe measures must be taken by the customer to ensure safety in the
event of incorrect, missing, or abnormal signals caused by broken signal lines,
momentary power interruptions, or other causes. Serious accidents may
result from abnormal operation if proper measures are not provided.
!Caution
Execute online edit only after confirming that no adverse effects will be
caused by extending the cycle time. Otherwise, the input signals may not be
readable.
!Caution
Confirm safety at the destination node before transferring a program to
another node or changing contents of the I/O memory area. Doing either of
these without confirming safety may result in injury.
Summary of Contents for CJ1M-CPU21
Page 1: ...Cat No W395 E1 03 CJ series Built in I O CJ1M CPU21 22 23 CJ1M CPU Units...
Page 2: ...CJ series Built in I O CJ1M CPU21 22 23 CPU Units Operation Manual Revised August 2004...
Page 3: ...iv...
Page 19: ...xx...
Page 79: ...50 Wiring Examples Section 3 3...
Page 217: ...188 Origin Search and Origin Return Functions Section 6 3...
Page 220: ...191 Built in Outputs Section 7 1...
Page 247: ...218 Built in Outputs Section 7 1...
Page 251: ...222 Combinations of Pulse Control Instructions Appendix A...
Page 255: ...226 Using Pulse Instructions in other CPU Units Appendix B...
Page 263: ...234 Index...
Page 265: ...236 Revision History...