Mitsubishi Electric MELSEC-F FX3U-CAN User Manual page 3

Before installation, operation, maintenance or inspection of this product, thoroughly read through and
understand this manual and all of the associated manuals. Also, take care to handle the module properly and
safely.
This manual classifies the safety precautions into two categories:
Depending on the circumstances, procedures indicated by
It is important to follow all precautions for personal safety.
Store this manual in a safe place so that it can be taken out and read whenever necessary. Always forward it
to the end user.
1. DESIGN PRECAUTIONS
• Make sure to have the following safety circuits outside of the PLC to ensure safe system operation even during
external power supply problems or PLC failure.
Otherwise, malfunctions may cause serious accidents.
1) Most importantly, have the following: an emergency stop circuit, a protection circuit, an interlock circuit for
opposite movements (such as normal vs. reverse rotation), and an interlock circuit (to prevent damage to the
equipment at the upper and lower positioning limits).
2) Note that when the PLC CPU detects an error, such as a watchdog timer error, during self-diagnosis, all
outputs are turned off. Also, when an error that cannot be detected by the PLC CPU occurs in an input/output
control block, output control may be disabled.
External circuits and mechanisms should be designed to ensure safe machinery operation in such a case.
• For the operating status of each node in the case of a communication error, see the FX
the product manual of each node.
Erroneous output or malfunctions may cause an accident.
• When executing control (data changes) to an operating PLC, construct an interlock circuit in the sequence program
so that the entire system operates safely. In addition, when executing control such as program changes and
operation status changes (status control) to an operating PLC, carefully read the manual and sufficiently confirm
safety in advance. Especially in control from external equipment to a PLC in a remote place, problems in the PLC
may not be able to be handled promptly due to abnormality in data transfer. Construct an interlock circuit in the
sequence program. At the same time, determine the actions in the system between the external equipment and the
PLC for protection against abnormalities in data transfer.
• Make sure to observe the following precautions in order to prevent any damage to the machinery or accidents due
to abnormal data written to the PLC under the influence of noise:
1) Do not bundle the main circuit line together with or lay it close to the main circuit, high-voltage line or load line.
Otherwise, noise disturbance and/or surge induction are likely to take place. As a guideline, lay the control line
at least 100mm (3.94") or more away from the main circuit or high-voltage lines.
2) Ground the shield wire or shield of a shielded cable.
Do not use common grounding with heavy electrical systems (refer to the manual of the PLC main unit).
Safety Precautions
(Read these precautions before use.)
Indicates that incorrect handling may cause hazardous conditions, resulting in death or severe
injury.
Indicates that incorrect handling may cause hazardous conditions, resulting in medium or slight
personal injury or physical damage.
(1)
and
may also cause severe injury.
-CAN user's manual and
3U
.
Reference
24
Reference
24