Structure Of Extension Registers And Extension File Registers; Initialization Of Extension Registers And Extension File Registers - Mitsubishi Electric MELSEC-Q Structured Programming Manual

FXCPU Structured Programming Manual
[Device & Common]
2.9.3

Structure of extension registers and extension file registers

One extension register consists of 16 bits. Extension registers can be used in 16-bit and 32-bit operation
instructions in the same way as data registers.
1) 16-bit type
One extension register (consisting of 16 bits) can handle a numeric value within the range from -32768 to
+32767.
High order
0
b15
Sign
0:Positive
1:Negative
A numeric value is usually read from and written to an extension register by an instruction.
Or a numeric value can be read and written directly from a display unit, display module or programming
tool.
2) 32-bit type
Two serial extension registers can express a 32-bit numeric value within the range from -2,147,483,648
to +2,147,483,647. (An extension register having a larger number handles high-order 16 bits, and an
extension register having a smaller number handles low-order 16 bits.)
High order
0
b31
Sign
0:Positive
1:Negative
• In the case of 32-bit data, when an extension register on the low-order side (Example: R0) is specified, the
subsequent number on the high-order side (Example: R1) is automatically occupied.
Either an odd or even device number can be specified for the low-order side, but it is recommended to
specify an even device number for the low-order side under consideration of the monitoring function of
display units, display modules and programming tools.
2.9.4

Initialization of extension registers and extension file registers

The contents of extension registers are backed up by the battery even when the power is turned OFF or when
the PLC mode switches from "STOP" to "RUN" if the PLC is the FX
Series if extension registers are changed to the latched (backed-up) type and an optional battery is attached.
For initializing extension registers, execute the data clear operation using a PLC program or GX Works2.
1. Initialization using a program
• When initializing some extension registers (R)
Example: When initializing (clearing) R0 to R199
Command
• When initializing extension registers and extension file registers in units of sector
(Sectors are not provided for extension registers and extension file registers in FX
Example: When initializing R0 to R4095 and ER0 to ER4095 (initializing two sectors starting from R0 and
ER0 respectively)
Command
R0,ER0(16-bit type)
1 0 1 0 1 0 1 0 1 0 1 0
R1,ER1(High-order 16 bits)
1 0 1 0 1 0 1 0 1 0 1 0
FMOVP
EN ENO
s d
K0 R0
n
K200
INITRP
EN ENO
s
R0
n
K2
2.9 Extension Register [R] and Extension File Register [ER]
Low order
1 0 1
b0
R0,ER0(Low-order 16 bits)
1 0 1 1 1 1 1 0 0 0 0 1
/FX
3U
2 Devices in Detail
Low order
1 1 1 0 0 0 0
b0
Series or the FX /FX
3UC 3G 3GC
/FX PLCs.)
3G 3GC
1
2
3
4
5
6
7
105