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12. PLC Timer Setting
Do not have the PLC timer setting to be done with the minimum setting.
Setting to “1” for 100msec timer turns ON at the timing from 0 to 100msec while 10msec timer
from 0 to 10msec for some PLC.
Therefore, the same process as when the timer is not set is held and may cause a failure such
as the actuator cannot get positioned to the indicated position number in Positioner Mode.
Set “2” as the minimum value for the setting of 10msec timer and when setting to 100msec, use
10msec timer and set to “10”.
13. Handling and Caution for Built-in Drive Cutoff Relay
The product equips a built-in drive cutoff relay, and it is necessary to be careful in handling. Use
the product with narrow understanding to the following notes.
• The drive cutoff relay built in our controllers is designed under assumption of limited frequency of use
such as a case to require emergency stop of a system, and frequent operation is not considered.
Therefore, in a condition to require high frequency of use of the drive cutoff relay such as a case to turn
ON/OFF the driving source in every setup change, the life of the relay may reach to the end in early
stage.
• The relay itself may not meet a sufficient safety demand level when it is used in a system that prioritizes
safety in the drive cutoff system. It is necessary to construct a system to meet the safety demand level
in a circuit that a customer prepares.
•
IAI products equip a built-in drive cutoff relay considering customer’s usage. However, as described
above, whether it can be used or not relies on such facts as the safety demand level and frequency of
drive cutoff. Please use it in limitation to the way to use as described below.
•
Do not expect reliability of the drive cutoff relay (Anything can do as long as driving source can be cut
off.)
•
Take around 5 times a day as a reference to turn ON/OFF the drive cutoff relay
•
Thermistor type (which the resistance gets high and restrains in-rush current in low temperature, and
resistance gets low and reduce loss in high temperature) in-rush current limiter circuit is equipped.
Therefore, to keep the thermistor temperature as low as possible when turning the power on is a key
point to make degradation slower on such components as the drive cutoff relay. As a reference, it is
preferred to have approximately 30 minutes for cooling after the driving source being cut off.
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