[Issue No.] T40-0006 [Page] 1/4

[Title] MELSEC-Q series CPU module battery backup time [Date of Issue] Mar., '06

reduction and the corrective actions

[Relevant Models] Q2MEM-2MBS

HEAD OFFICE : TOKYO BUILDING, 2-7-3 MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN

NAGOYA WORKS : 1-14, YADA-MINAMI 5-CHOME, HIGASHI-KU, NAGOYA, JAPAN

TECHNICAL BULLETIN

Thank you for your continued support of Mitsubishi programmable logic controllers, MELSEC-Q series.

This bulletin provides information of cautions for a battery backup time when using the MELSEC-Q series memory card.

1. Precautions

Based on the stricter process rule s and the contribut ions t o environm enta l conservati on, such as lead-free, com pli ance to

RoHS directives are required, we have changed the memory (SR AM) to m a intai n the producti on.

The new mem ory (SRAM ) satisfi es the batt ery backup t im e guara nteed by Mit subishi . However, with t he m em ory change,

the actual service value of battery backup t im e has been drasti cally shorter as descri bed in it em 2 (2); t his i s caused by the

mem ory’s characteri stic s, i.e., it requires m ore current for backup at power fail ure than the form er one.

It is recommended to eliminate the affect of battery voltage reduction on the system by carrying out t he corrective actions in

item 3.

[Issue No.] T40-0006 [Page] 2/4

[Title] MELSEC-Q series CPU module battery backup time [Date of Issue] Mar., '06

reduction and the corrective actions

[Relevant Models] Q2MEM-2MBS

HEAD OFFICE : TOKYO BUILDING, 2-7-3 MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN

NAGOYA WORKS : 1-14, YADA-MINAMI 5-CHOME, HIGASHI-KU, NAGOYA, JAPAN

TECHNICAL BULLETIN

2. Relevant Models and Changes

(1) Relevant models

Table 1 below shows the CPU module models with new memory (SRAM) of the memory card.

Table 1 Models with new memory (SRAM)

Manufacturer control number *2

Model *1 Memory change time

Before change After change

Q2MEM-2MBS Manufactured from March, 2006

" D "

D or earlier

" E "

E or later

*1: The Q2MEM-1MBS is not applicable for decrease of a battery backup time.

*2: Checking the manufacturer control number

Manufacturer control number can be checked with the number (the 3rd digit from the left) marked on the lower

right of the SRAM card back label. Manufacturer control number “E” or later is the target memory card.

60EN

WRITE PROTECT

BATTERY

(-)Side

LOCKQ2MEM-2MBS

Manufacturer control number

SRAM card back label

For manufacturer control number “C” or earlier, the number is marked on the upper right.

Do not subject to mechanical shock!

Do not expose to extreme temperrature,

Manufacturer control number

3LCN

SRAM card back label