Siemens 500 NIM - Manual (Page 67)

NIM Primitives 4-14 SIMATIC TIWAY I Series 500 NIM User Manual
4.6 Data Element Types and Formats
The data element types (TTs) and their length (in bytes) are defined in
Table 4-4. Figure 4-4 through Figure 4-15 show the format of the data
elements.
Table 4-4 Data Element Types and Formats
TT Data Element Type
Length
(in bytes)
0 Instruction Memory (L) 2
1 Variable Memory (V) 2
2 Constant Memory (K) 2
3 Discrete Input (X) 1
4 Discrete Output (Y) 1
5 Control Register (CR) 1
6 Discrete Input Packed (X) 1
7 Discrete Output Packed (Y) 1
8 Control Register Packed (CR) 1
9 Word Input (WX) 2
A Word Output (WY) 2
B XY Force 1
C CR Force 1
D Word Force 3
E Timer-Counter Preset (TCP) 2
F Timer-Counter Current (TCC) 2
10 Drum Step Preset (DSP) 1
11 Drum Step Current (DSC) 1
12 Drum Count Preset (DCP) 2
17 Secondary System Status* 4
** 20 or 60 Loop Gain 4
** 21 or 61 Loop Reset 4
** 22 or 62 Loop Rate 4
** 23 or 63 Loop High Alarm 4
** 24 or 64 Loop Low Alarm 4
** 25 or 65 Loop Process Variable 4
* These TT types are read-only data elements.
# This TT type is a write-only data element.
** Format
2x, 3x, and 4x = IBM format
6x, 7x, and 8x = IEEE format