Changing A Module Directly - Mitsubishi Electric MELSEC iQ-R Series Manual

3.5

Changing a Module Directly

This section describes the method to change a module directly.
The direct change is not available for redundant function modules as a method of the online module change.
Presettings
To perform a direct online module change, "Direct change setting" must be set to "Enable" in advance.
Navigation window  [Parameter]  Module model name  [CPU Parameter]  "RAS Setting"  "Online module
change setting"  "Direct change setting"
■When "Direct change setting" is set to "Enable"
An error occurs when a module is removed in direct change. However, setting "Direct change setting" to "Enable" allows the
replacement to continue without a stop even though "CPU Module Operation Setting at Error Detection" is set to "Stop". The
following table shows the target parameter settings and errors.
Parameter setting item
CPU Parameter  RAS Setting 
CPU Module Operation Setting at
Error Detected
System Parameter  I/O Assignment
Setting (each module)  CPU
Module Operation Setting at Error
Detected
None
None
If any of the errors above remains and affects the system, set "Direct change setting" to "Disable" and perform an online
module change using special relays and special registers.
In the multiple CPU system, when any of the CPU modules is set to "Enable" in "Direct change setting" (including the case
where other CPU modules are set to "Disable" in "Direct change setting"), all the modules continue each operation without
stopping even if any of the errors above occurs.
In a redundant system, the above errors, which cause system switching, remain. Thus, the systems are not switched. In
addition, the above errors due to module mounting/removal during operation remain regardless of the parameter setting.
Thus, the systems are not switched even if a module is removed or has a failure on the control system.
■Precautions for direct change
If direct change is predicted, always configure safety circuits external to the programmable controller to ensure that the entire
system operates safely and perform the following.
• After ensuring the system safety by configuring safety circuits, perform direct change.
• To replace a module that gives outputs to external devices, configure an external interlock circuit on a program so that the
outputs are turned off interlocking with safety circuits.
• Before performing direct change on a system that is already operating, make sure to confirm that direct change does not
affect the system.
Before removing a module, always shut off the external power supply input to the module.
Checks before replacement
The following shows the check procedure before replacement. In this procedure, stop the control of the online module change
target module for safe online module change.
The procedure is the same as that of the online module change using special relays and special registers. Refer to the
following.
Page 30 Checks before replacement
Parameter setting
Module Verify Error: "Stop"
Fuse Blown: "Stop"
Moderate: Stop
Critical: Stop
None
None
Error code
2400H
2401H
2420H
1200H
2450H
2440H
2443H
3 REPLACEMENT PROCEDURE
3.5 Changing a Module Directly
Error name
Module verification error
Module verification error
Fuse blown error
Module moderate error
Module major error
Module major error
Module major error
3
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