Data Register And File Register [D]; Numbers Of Data Registers And File Registers - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
4.9

Data Register and File Register [D]

Data registers are devices for storing numeric data. File registers are handled as the initial values of data
registers.
Each data register or file register stores 16-bit data (whose most significant bit specifies the positive or
negative sign). Combined two data registers or file registers can store 32-bit numeric data (whose most
significant bit specifies the positive or negative sign).
4.9.1

Numbers of data registers and file registers

The table below shows numbers of data registers and file registers. (Numbers are assigned in decimal.)
1. FX /FX PLC
3U 3UC
Latched (battery backed)
General
type (backed up by battery
against power failure)
D0 to D199
*1
200 points
2. FX PLCs
3G
General type
D0 to D127
128 points
*1. This area is not latched (battery backed). It can be changed to the latched (battery backed) area by
setting parameters.
*2. This area is latched (battery backed). It can be changed to the non-latched (non-battery-backed) area
by setting parameters.
*3. The latch (battery backup) characteristics cannot be changed using parameters.
*4. Data registers D1000 and later can be used as file registers in units of 500 points by setting
parameters.
*5. These registers can be changed to the latched type by the parameter setting when the optional
battery is used. However, the latched range cannot be set.
When computer link PCs or parallel link is used, some data registers are occupied for the link.
→ For the functions and operations of file registers, refer to Subsection 4.9.4.
Data registers
Fixed latched (battery
type backed) type
(backed up by battery
against power failure)
D200 to D511 D512 to D7999
*2
312 points 7488 points
Data registers
Latched type
General type
(EEPROM keep)
D1100 to D7999
D128 to D1099
972 points
6900 points
4.9 Data Register and File Register [D]
Special type
D8000 to D8511
*3*4
512 points
7000 points maximum
File registers
(latched (EEPROM
Special type
keep) type)
D8000 to D8511
D1000
*5
512 points
7000 points maximum
→ Refer to the Data Communication Edition.
4 Devices in Detail
File registers
(latched (battery
backed) type)
*4
D1000 and later
*4
and later
131
1
2
3
4
5
6
7
8
9
10