Mitsubishi FX3UC Series User Manual

380
FX3UC Series Programmable Controllers
User’s Manual - Hardware Edition
11 Memory Cassette/Battery
11.5 FX3U-32BL (Battery)
11.5 FX3U-32BL (Battery)
The main unit of the PLC has a built-in battery.
When the battery voltage drops, the BAT LED lights, and the special auxiliary relay (M8005 or M8006) turns
on. In this case, replace the battery FX
3U-32BL.
11.5.1 Specifications
Battery voltage can be monitored with PLC data register D8005.
11.5.2 Battery Purpose
1. The battery is required to retain (backup) program memory and "keep device" data and
maintain clock operation in the event of a power outage.
2. Battery Handling
When the battery voltage is low, a "BAT" LED lights (red) while the power is ON, and M8005 and M8006 are
switches ON.
Although the battery will continue to function for approximately 1 month after the "BAT" LED switches ON, a
replacement battery should be ordered and installed as soon as possible.
→ For the replacement procedures, refer to Subsection 12.4.3.
11.5.3 Special "battery low-voltage" device & notification program example
Prepare a system which allows constant external monitoring of the battery status, using an indicator lamp,
etc.
• M8005
Y001 is output when a battery low-voltage condition occurs.
• M8006
Battery low-voltage is latched.
• D8005
Battery voltage can be monitored.
Item Specifications
Nominal voltage 3V
Data Retained By Backup Battery
Program memory Internal RAM parameters, programs, device comments, file registers
Device memory
• Auxiliary relay, state (for annunciator included), timer (cumulative type), counter, data
register keep device
• Extended register
• Sampling trace result
Current time Current time clock
M8005
Battery low-voltage
Y001

Mitsubishi FX3UC Series Specifications

General

Brand	Mitsubishi
Model	FX3UC Series
Category	Controller
Language	English