85
Specifications Section 2-1
Online editing When the CPU Unit is in MONITOR or PROGRAM mode, 
multiple program sections (“circuits”) of the user program can 
be edited together. This function is not supported for block 
programming areas.
(With the CX-Programmer is used, multiple program sections 
of the user program can be edited together. When a Pro-
gramming Console is used, the program can be edited in 
mnemonics only.)
Programming Manual: 
1-2 Operating Modes 
and 7-2-3 Online Edit-
ing
Program protection Overwrite protection: Set using DIP switch.
Copy protection: Password set using CX-Programmer or Pro-
gramming Consoles.
Programming Manual: 
6-4-6 Program Protec-
tion
Error check User-defined errors (i.e., user can define fatal errors and 
non-fatal errors)
The FPD(269) instruction can be used to check the execution 
time and logic of each programming block.
FAL and FALS instructions can be used with the CJ1-H and 
CJ1M CPU Units to simulate errors.
11-2-5 Error Messages
Programming Manual: 
6-5 Diagnostic Func-
tions and 6-5-3 Failure 
Alarm Functions
Error log Up to 20 errors are stored in the error log. Information 
includes the error code, error details, and the time the error 
occurred.
A CJ1-H or CJ1M CPU Unit can be set so that user-defined 
FAL errors are not stored in the error log.
Programming Manual: 
6-4-1 Error Log
Serial communications Built-in peripheral port: Programming Device (including Pro-
gramming Console) connections, Host Links, NT Links
Built-in RS-232C port: Programming Device (excluding Pro-
gramming Console) connections, Host Links, no-protocol 
communications, NT Links
2-5-1 Serial Communi-
cations System
Programming Manual: 
6-3 Serial Communica-
tions Functions
Serial Communications Unit (sold separately): Protocol mac-
ros, Host Links, NT Links
Clock Provided on all models. 
Accuracy:  Ambient temperature Monthly error
55°C −3.5 min to +0.5 min
25°C −1.5 min to +1.5 min
0°C −3 min to +1 min
Note Used to store the time when power is turned ON and 
when errors occur.
Programming Manual: 
6-4-5 Clock Functions
Power OFF detection time AC Power Supply Unit: 10 to 25 ms (not fixed)
DC Power Supply Unit PD025: 2 to 5 ms; PD022: 2 to 10 ms 
10-3 Power OFF Oper-
ation
Power OFF detection delay 
time
0 to 10 ms (user-defined, default: 0 ms)
Note Not supported when the CJ1W-PD022 Power Supply 
Unit is mounted.
Programming Manual: 
6-4-4 Power OFF 
Detection Delay Time
Memory protection Held Areas: Holding bits, contents of Data Memory and 
Extended Data Memory, and status of the counter Comple-
tion Flags and present values.
Note If the IOM Hold Bit in the Auxiliary Area is turned ON, 
and the PLC Setup is set to maintain the IOM Hold Bit 
status when power to the PLC is turned ON, the con-
tents of the CIO Area, the Work Area, part of the Auxil-
iary Area, timer Completion Flag and PVs, Index 
Registers, and the Data Registers will be saved for up 
to 20 days.
9-2-3 Data Area Prop-
erties
Sending commands to a Host 
Link computer
FINS commands can be sent to a computer connected via 
the Host Link System by executing Network Communications 
Instructions from the PLC.
2-5-2 Systems
Item Specifications Reference