Mitsubishi Melsec-Q Series User Manual page 290

SRAM card
Q3MEM-8MBS
*1: The power-on time ratio indicates the ratio of programmable controller power-on time to one day (24 hours).
(When the total power-on and power-off times are 12 hours for each, the power-on time ratio is 50%).
*2: The manufacturing control number (the third digit from the leftmost) is written on the label on the back of the SRAM card
(as shown in Figure 11.7).
*3: Indicates the battery life when the SRAM card is installed in the High Performance model QCPU with the serial number
(first five digits) is "04012" or later.
For the battery life for those of "04011" or lower, refer to Appendix 2.
*4: The actual value may vary depending on ambient temperature.
●
Use the battery within the time shown by the guaranteed value of the battery life.
●
If the battery may be used exceeding the time shown by the guaranteed battery life value, perform the following.
• Perform ROM operation to protect a program even if the battery dies at the programmable controller power-off.
• Back up programs and data after SM52 turned on (within the backup time after an alarm).
●
Note that the SRAM card battery is consumed even while the programmable controller is powered ON with the CPU
module battery connected.
●
When the special relay showing battery low, SM52 turned on, immediately change the battery.
Even if an alarm has not yet occurred, it is recommended to replace the battery periodically according to the conditions
of use.
●
The SRAM card is not available for the Basic model QCPU.
11 - 30
Power-on
Guaranteed value
*1
time ratio
(MIN)
36,300hours
0%
4.1 years
43,800hours
30%
5.0 years
43,800hours
50%
5.0 years
43,800hours
70%
5.0years
43,800hours
100%
5.0 years
Figure 11.7 Label on the back of SRAM card
*3
Battery life
Actual service value
*4
(Backup power time
(Reference value)
43,800hours
5.0 years
43,800hours
5.0 years
43,800hours
5.0 years
43,800hours
5.0 years
43,800hours
5.0 years
Manufacturer
control number
After SM52
turned on.
after an alarm)
50 hours
50 hours
50 hours
50 hours
50 hours