2.8 Global Devices and Local Devices
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Global devices
● While a global device has a unique number throughout the entire program, a local device has
a unique number inside each program block.
● For example, "Global device DT100" refers to the same data memory in program blocks A
and B. Therefore, data of DT100 is overwritten if the relevant information is revised in either
program block A or B.
● Global devices are utilized when the operation memory is required to be shared between
multiple program blocks (PB) for external input/output or other purposes.
Program block A Program block B
DT100
Refer to the same area
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Local devices
● If data of local device dt10 is changed in either program block A or B, since the local device
is allocated to different data memory, the data for one program block will not be overwritten
by the other program block.
Program block A
Program block B
_DT10 _DT10Same name but separated
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List of available memory areas for local devices (●: Available)
Bit device 16-Bit device: 32-Bit device:
X, Y, R, L, T, C
P, E, SR, IN,
OT
DT.n, LD.n
WX, WY, WR,
WL, DT, LD
SD, WI, WO,
UM
TS, CS,TE, CE
● ● ● ●
2.8 Global Devices and Local Devices
2-46 WUME-FP7CPUPGR-12
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