Instruction manual

6 - 7
6 INSPECTION AND MAINTENANCE
6.5 Battery
The battery installed in the Motion CPU module is used for data retention during the
power failure of the program memory and latch device. Special relays (SM51, SM52,
SM58 or SM59) turn on due to the decrease of battery voltage. Even if the special
relays turn on, the program and retained data are not erased immediately.
However, if these relays are overlooked, the contents may be erased.
After relay SM51 or SM58 turns on, replace the battery quickly within the data
retention time for power failure (3 minutes).
POINT
(1) SM51 or SM58 turns on when the battery voltage falls below the specified
value, and remains ON even after the battery voltage is recovered to the
normal value. SM51 or SM58 turns off by power supply on again or reset.
(2) After SM51, SM52, SM58 or SM59 turns on, replace the battery quickly.
• SM51 or SM52 turns on at the battery voltage 2.5V or less.
• SM58 or SM59 turns on at the battery voltage 2.7V or less.
(3) If SM51 turns on, the details for the programs, parameters, motion device(#),
latch range device and absolute position data of SRAM built-in Motion CPU
module cannot be guaranteed.
It is recommended to back-up the data periodically.
(4) For Q173DSCPU/Q172DSCPU, whether or not to check the battery of Motion
CPU can be set in the system basic setting of system setting. If "Not battery
check" is set, a self-diagnosis error will not occur and the 7-segment LED
"BT1" or "BT2" is not also displayed.
Refer to the "Q173D(S)CPU/Q172D(S)CPU Motion controller Programming
Manual (COMMON)" for details.