447
Program Protection
Section 8-7
Auxiliary Area Flags and Bits Related to Password Protection
8-7-2
Write Protection
Write-protection
Using the DIP Switch
The user program can be write-protected by turning ON pin 1 of the CPU
Unit’s DIP switch. When this pin is ON, it won’t be possible to change the user
program or parameter area (e.g., PLC Setup and routing tables) from the CX-
Programmer. This function can prevent the program from being overwritten
inadvertently at the work site.
It is still possible to read and display the program from the CX-Programmer
when it is write-protected.
CPU Unit DIP Switch
Confirming the User Program Date
The dates the program and parameters were created can be confirmed by
checking the contents of A90 to A97.
Name
Bit
address
Description
UM Read Protection
Flag
A99.00
Indicates whether or not the PLC (the entire user
program) is read-protected.
OFF: UM read protection is not set.
ON: UM read protection is set.
Task Read Protection
Flag
A99.01
Indicates whether or not selected program tasks
are read-protected.
OFF: Task read protection is not set.
ON: Task read protection is set.
Program Write Protec-
tion for Read Protec-
tion
A99.02
Indicates whether or not the write protection
option has been selected to prevent overwriting of
password-protected tasks or programs.
OFF: Overwriting allowed
ON: Overwriting prohibited (write-protected)
Enable/Disable Bit for
Program Backup
A99.03
Indicates whether or not a backup program file
(.OBJ file) can be created when UM read protec-
tion or task read protection is set.
OFF: Creation of backup program file allowed
ON: Creation of backup program file prohibited
Pin
Name
Settings
SW1
User Program Memory Write Protection
ON: Protected
OFF: Not protected
Summary of Contents for CP1L-EL20DR-D
Page 3: ...CP1L EL20D CP1L EM30D CP1L EM40D CP1L EL EM CPU Unit Operation Manual Produced July 2017...
Page 4: ...iv...
Page 10: ...x...
Page 22: ...xxii...
Page 34: ...xxxiv Software Licenses and Copyrights 7...
Page 192: ...158 Trial Operation and Debugging Section 5 3...
Page 250: ...216 Automatic Clock Adjustment and Specifying Servers by Host Name Section 6 7...
Page 666: ...632 Trouble Shooting Section 11 7...
Page 696: ...662 Standard Models Appendix A...
Page 805: ...771 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 806: ...772 Connections to Serial Communications Option Boards Appendix F...
Page 836: ...802 PLC Setup Appendix G...
Page 838: ...804 TCP Status Transitions Appendix H...
Page 840: ...806 Ethernet Network Parameters Appendix I...
Page 842: ...808 Buffer Configuration CP1L EL EM Appendix J...
Page 844: ...810 Ethernet Specifications Appendix K...
Page 851: ...Index 817 work words 118 write protection 447...
Page 852: ...818 Index...
Page 854: ...820 Revision History...
Page 855: ......