Precautions On The System Configuration - Mitsubishi Electric L26CPU-BT User Manual

5.2.3

Precautions on the system configuration

(1) When using the remote station
This section describes notes to be paid attention upon system design to prevent an incorrect input from a remote
station.
(a) When powering on or off
Start the data link after turning on the power of the remote station.
Turn off the power of the remote station after stopping the data link.
Master module
(data link status)
Remote station
(power status)
(2) During momentary power failure of remote station
When a momentary power failure occurs in the power (24VDC) supplied to remote station, incorrect input may
occur.
• Cause for incorrect input due to a momentary power failure
The remote station hardware uses the power by internally converting the module power (24VDC) to 5VDC.
When a momentary power failure occurs in a remote station, the following condition occurs: (Time for the 5VDC
power in the remote station to turn off) > (Response time for input module on and off)
Therefore, incorrect input occurs when a refresh is performed within the time indicated by 1) in the figure below.
Remote station
(module power supply and input
external supply power)
Remote station
(internal 5 V DC)
Input (Xn)
Data link start
During operation
During stop
ON
OFF
When the input external power supply turns OFF, the
input (Xn) turns OFF after the response time for the
input module to change from ON to OFF.
CHAPTER 5 SYSTEM CONFIGURATION
Data link stop
1)
5
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