1
SAFETY PRECAUTIONS
(Read these precautions before use.)
Before using this product, please read this manual and the relevant manuals introduced in this manual carefully and pay full 
attention to safety in order to handle the product correctly.
This manual classifies the safety precautions into two categories: [ WARNING] and [ CAUTION].
Depending on the circumstances, procedures indicated by [ CAUTION] may also cause severe injury.
It is important to follow all precautions for personal safety.
Store this manual in a safe place so that it can be read whenever necessary. Always forward it to the end user.
[DESIGN PRECAUTIONS]
[DESIGN PRECAUTIONS]
WARNING
● Make sure to set up the following safety circuits outside the tension controller to ensure safe system 
operation even during external power supply problems or tension controller failure. Otherwise, 
malfunctions may cause serious accidents.
-  Note that when an error occurs in a relay or transistor of an output circuit, the output might stay on 
or off. For output signals that may lead to serious accidents, external circuits and mechanisms 
should be designed to ensure safe machinery operation in such a case.
● Most importantly, set up 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 torque limits and upper and lower tension 
limits).
● In an output circuit, when a load current exceeding the current rating or an overcurrent caused by a 
load short-circuit flows for a long time, it may cause smoke and fire. To prevent this, configure an 
external safety circuit, such as a fuse.
● For the operating status of each station after a communication failure of the network, refer to relevant 
manuals for the network. Incorrect output or malfunction may result in an accident.
CAUTION
● If a power failure or an abnormal voltage drop occurs, the tension controller stops, and output is 
turned off.
WARNING
Indicates that incorrect handling may cause hazardous conditions, resulting in 
death or severe injury. 
CAUTION
Indicates that incorrect handling may cause hazardous conditions, resulting in 
minor or moderate injury or property damage.