Siemens CIM Operating Manual page 12

Application and functions
1.4 Universal Data Model
I, Q, M, V constructed a data model to simulate the process image in PLC.
Naming rule for the UDM address: address type + short data type + start address. No byte
alignment, for example, VW3 means the word consist of Byte 3 and Byte 4 in area V.
The UDM address is case insensitive.
Data type (Short Length
data type)
bool (x) 1 bit
byte (b) 8 bit
word (w) 16 bit
double-word (dw) 32 bit
long-word (lw) 64 bit
short-int (si) 8 bit
int (i) 16 bit
double-int (di) 32 bit
long-int (li) 64 bit
Real (r) 32 bit
long-real (lr) 64 bit
short-unsigned 8 bit
(su)
unsigned (u) 16 bit
double -unsigned 32 bit
(du)
long-unsigned (lu) 64 bit
12
Value range
0 ~ 1
0 ~ FF
0 ~ FFFF
0 ~ FFFFFFFF
0 ~ FFFFFFFFFFFFFFFF
-128 ~127
-32768 ~ 32767
-2147483648 ~ 2147483647
-9223372036854775808 ~
9223372036854775807
-3.4E38 ~ +3.4E38
-1.797E308 ~ +1.797E308
0 ~ 255
0 ~ 65535
0 ~ 4294967295
0 ~ 18446744073709551615 0-504
I Q M
（512 （512 （512
Bytes） Bytes） Bytes）
0.0-511.7 0.0-511.7 0.0-511.7
0-511 0-511 0-511
0-510 0-510 0-510
0-508 0-508 0-508
0-504 0-504 0-504
0-511 0-511 0-511
0-510 0-510 0-510
0-508 0-508 0-508
0-504 0-504 0-504
0-508 0-508 0-508
0-504 0-504 0-504
0-511 0-511 0-511
0-510 0-510 0-510
0-508 0-508 0-508
0-504 0-504
Operating Manual, 11/2022, A5E51250518-AC
V
(W: 896 Bytes
R: 1024 Bytes)
0.0-895.7 0.0-
1023.7
0-895 0-1023
0-894 0-1022
0-892 0-1020
0-888 0-1016
0-895 0-1023
0-894 0-1022
0-892 0-1020
0-888 0-1016
0-892 0-1020
0-888 0-1016
0-895 0-1023
0-894 0-1022
0-892 0-1020
0-888 0-1016
CIM