Mitsubishi FX3UC Series User Manual

270
FX3UC Series Programmable Controllers
User’s Manual - Hardware Edition
9 CC-Link/LT Built-in master ability (Only FX3UC-32MT-LT)
9.7 Design Precautions
FX3UC Series Programmable Controllers
User’s Manual - Hardware Edition
9.7 Design Precautions
9.7.1 Prevention of erroneous inputs and outputs to/from remote I/O modules
In order to prevent erroneous inputs to and outputs from remote I/O modules, design the system under
consideration of the contents described below.
1. When setting the power to ON or OFF
When using a power supply adapter or dedicated power supply, turn ON the power of the remote I/O units
(power supply adapter and dedicated power supply) before starting data link.
Stop the data link first, and then turn OFF the power to the remote I/O modules (power adapter or dedicated
power supply).
2. When the power is interrupted instantaneously in a remote I/O module
When the power (24V DC) supplied to a remote I/O module is interrupted instantaneously, erroneous inputs
may occur.
Cause of erroneous inputs due to instantaneous power interruption
The hardware of a remote I/O module converts the unit power (24V DC) into 5V DC before using it.
If instantaneous power interruption occurs in a remote I/O module:
Time until 5V DC inside remote I/O module turns OFF > Response time for "ON
→ OFF" of input unit
As a result, if refresh is executed in the period shown in (A) below, erroneous inputs occur.
(Erroneous inputs may occur especially while the input response time is set to high-speed input type.)
Built-in master
(data link status)
Remote I/O module
(power supply status)
Executing
Stopped
ON
OFF
Data link start Data link stop
Remote I/O module
(Unit power supply and external
power supply to input area)
Remote I/O module
(internal 5V DC)
(A)
When the external power supply to the
input area is set to ON, the input
(Xn) turns ON after the response time for
"OFF
→ ON" of the input unit.
When the external power supply to the
input area is set to OFF, the input (Xn)
turns OFF after the response time for
"ON
→ OFF" of the input unit.
Input (Xn)

Mitsubishi FX3UC Series Specifications

General

Brand	Mitsubishi
Model	FX3UC Series
Category	Controller
Language	English