Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
E-26
5 Buffer Memory (BFM)
5.4 Buffer Memory Details
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX
3U
-4DA (4-channel Analog Output)
3. Cautions regarding offset/gain data change
• If the analog value specification mode (mode 1 or 4) is used, the offset/gain cannot be changed. However,
the characteristics can be changed as those in the output mode 1 or 4 by setting the following offset and
gain data in the output mode 0 or 2.
gain data in the output mode 0 or 2.
• The offset and gain data should be set before the value write command BFM #9 is executed.
• The resolution cannot be increased by changing the output characteristics.
• When the value specified as the output mode (BFM #0) is changed, the initial value of offset and gain data
• The resolution cannot be increased by changing the output characteristics.
• When the value specified as the output mode (BFM #0) is changed, the initial value of offset and gain data
in each output mode will be automatically written.
• Even if the output characteristics are changed, the actual valid output range will not be changed:
-10 V to +10 V for the voltage output mode, and 0 mA to 20 mA in the current output mode.
→ For a detailed description of output characteristics change, refer to Chapter 7.
5.4.7
BFM #19: Data change prohibition of setting change
Setting range: K3030 or other than K3030
Initial value: K3030
Numeric data type: Decimal (K)
Setting in the following buffer memory areas is prohibited.
• BFM #0 (output mode setting Output mode setting)
• BFM #0 (output mode setting Output mode setting)
BFM #5 (output setting upon PLC stop)
BFM #9 (offset/gain setting value write command)
BFM #10 to #13 (offset data)
BFM #14 to #17 (gain data)
BFM #20 (initialization function)
BFM #32 to #35 (data to be output upon PLC stop)
BFM #38 (upper/lower limit function setting)
BFM #41 to #48 (upper and lower limit values of upper/lower limit function)
BFM #50 (corrective function setting by load resistance)
BFM #51 to #54 (load resistance values)
BFM #60 (status automatic transfer function setting)
BFM #61 (Error status data automatic transfer-to data register specification)
BFM #62 (Upper/lower limit function status with automatic transfer to specified register specification)
BFM #63 (Disconnection detection status with automatic transfer to specified data register specification)
BFM #9 (offset/gain setting value write command)
BFM #10 to #13 (offset data)
BFM #14 to #17 (gain data)
BFM #20 (initialization function)
BFM #32 to #35 (data to be output upon PLC stop)
BFM #38 (upper/lower limit function setting)
BFM #41 to #48 (upper and lower limit values of upper/lower limit function)
BFM #50 (corrective function setting by load resistance)
BFM #51 to #54 (load resistance values)
BFM #60 (status automatic transfer function setting)
BFM #61 (Error status data automatic transfer-to data register specification)
BFM #62 (Upper/lower limit function status with automatic transfer to specified register specification)
BFM #63 (Disconnection detection status with automatic transfer to specified data register specification)
Specify the following value as the setting change prohibition mode (BFM #19).
1. Cautions regarding setting of the setting change prohibition mode
• While changing the setting value, the output is stopped, and H0000 is automatically written in the output
status (BFM #6).
At the completion of writing, the output status (BFM #6) will automatically change to H1111, and the output
will be restarted.
At the completion of writing, the output status (BFM #6) will automatically change to H1111, and the output
will be restarted.
2. Cautions regarding EEPROM writing
If data is set in BFM #0, #5, #10 to #17, #19, #32 to #35, #50 to #54 or #60 to #63, the data will be written in
the EEPROM of FX
the EEPROM of FX
3U-
4DA.
Do not turn off power immediately after writing values in these buffer memories
The maximum number of EEPROM rewritable times is 10,000. Therefore, when creating a program, do not
frequently write data in the above buffer memories (BFM).
The maximum number of EEPROM rewritable times is 10,000. Therefore, when creating a program, do not
frequently write data in the above buffer memories (BFM).
Offset data
Gain data
Change characteristics from output mode 0 to 1
0
16000
Change characteristics from output mode 2 to 4
0
16000
Set value
Description
K3030
permits data change
Other than K3030
disables data change