814
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
36 Operation of Special Devices (M8000 -, D8000 -)
36.1 Special Device List (M8000 -, D8000 -)
36.1.2
Special Data Register (D8000 to D8511)
Number and name
Content of register
Applicable model
FX
3U
FX
3UC
Correspond-
ing special
device
FX
1S
FX
1N
FX
2N
FX
1NC
FX
2NC
PLC Status
D 8000
Watchdog
timer
Default value is shown on the right (in 1ms steps)
(Writes from system ROM at power ON)
Value overwritten by program is valid after END or
WDT instruction execution.
→
Refer to Subsection 36.2.2.
200
200
–
200
200
200
200
200
[D]8001
PLC type and
system version
24
24
D8101
*1
22
26
24
26
24
[D]8002
Memory capacity
•
2...2K steps
•
4...4K steps
•
8...8K steps
•
If 16K steps or more
"K8" is written to D8002 and "16" or "64" is written
to D8102.
3
8
3
8
D8102
3
2
3
8
3
4
8
3
8
3
4
8
[D]8003
Memory type
Type of RAM/EEPROM/EPROM cassette or ON/
OFF status of memory protect switch is stored.
3
3
–
3
3
3
3
3
[D]8004
Error number M
3
3
M8004
3
3
3
3
3
[D]8005
Battery voltage
3
3
M8005
–
–
3
–
3
[D]8006
Low battery voltage
detection level
Default:
•
FX
2N
and FX
2NC
PLCs: 3.0V (in units of 0.1V)
•
FX
3U
and FX
3UC
PLCs: 2.7V (in units of 0.1V)
(Writes from system ROM at power ON)
3
3
M8006
–
–
3
–
3
*1.
The corresponding special device D8101 is available only in FX
3U
and FX
3UC
PLCs.
No corresponding device is available in FX
1S
, FX
1N
, FX
2N
, FX
1NC
, and FX
2NC
PLCs.
BCD converted value
2 4
1 0 0
Indicated on the right
Version 1.00
Present
value
Type of memory
Protect
switch
00H
RAM memory cassette
–
01H
EPROM memory cassette
–
02H
EEPROM memory
cassette or flash memory
cassette
OFF
0AH
EEPROM memory
cassette or flash memory
cassette
ON
10H
Built-in memory in PLC
–
BCD converted value
8 0 6 0
8060 to 8068 (when M8004 is ON)
BCD converted value
(in units of 0.1V)
3 0
Battery voltage present value (Example: 3.0V)