654
Replacing User-serviceable Parts
Section 13-2
13-2 Replacing User-serviceable Parts
The following parts should be replaced periodically as preventative mainte-
nance. The procedures for replacing these parts are described later in this
section.
• Battery (backup for the CPU Unit’s internal clock and RAM)
Battery Functions
The battery maintains the internal clock and the following data of the CPU
Unit’s RAM while the main power supply is OFF.
• Retained regions of I/O memory (such as the Holding Area and DM Area)
If the battery is not installed or battery voltage drops too low, the internal clock
will stop and the data in RAM will be lost when the main power supply goes
OFF.
Battery Service Life and
Replacement Period
At 25
°
C, the maximum service life for batteries is five years whether or not
power is supplied to the CPU Unit while the battery is installed. The battery’s
lifetime will be shorter when it is used at higher temperatures.
The following table shows the approximate minimum lifetimes and typical life-
times for the backup battery (total time with power not supplied).
Note
The minimum lifetime is the memory backup time at an ambient temperature
of 55
°
C. The typical lifetime is the memory backup time at an ambient temper-
ature of 25
°
C.
Model
Approx.
maximum lifetime
Approx. minimum
lifetime (See note.)
Typical lifetime
(See note.)
CP1L-EM
@@
D
@
-D
CP1L-EL
@@
D
@
-D
5 years
13,000 hours
(approx. 1.5 years)
43,000 hours
(approx. 5 years)
Memory Backup Time
Ambient temperature
This graphic is for reference only.
5 yr
4 yr
3 yr
2 yr
1 yr
CP1L-EL/EM CPU Unit
25
°
C
40
°
C
55
°
C
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: ......