Fx 3U -32Bl (Battery); Specifications; Battery Purpose; Special "Battery Low-Voltage" Device & Notification Program Example - Mitsubishi FX3UC SERIES User Manual

FX Series Programmable Controllers
3UC
User's Manual - Hardware Edition
11.5 FX -32BL (Battery)
3U
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

11.5.1 Specifications

Item
Nominal voltage
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.
Program memory
Device memory
Current time
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.
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
M8005
Battery low-voltage
• M8006
Battery low-voltage is latched.
• D8005
Battery voltage can be monitored.
380
-32BL.
3U
Specifications
3V
Internal RAM parameters, programs, device comments, file registers
• Auxiliary relay, state (for annunciator included), timer (cumulative type), counter, data
register keep device
• Extended register
• Sampling trace result
Current time clock
→ For the replacement procedures, refer to Subsection 12.4.3.
Y001 is output when a battery low-voltage condition occurs.
Y001
Data Retained By Backup Battery
11 Memory Cassette/Battery
11.5 FX3U-32BL (Battery)