Siemens SINUMERIK 808D ADVANCED Commissioning Manual page 163

Constant definition
Constant input
Constant "1"
Constant "2"
Zero output definition
Data type
bit
byte
word
double-word
Structure of symbol tables
All the addresses in the PLC subroutine library are programmed with symbols. All the signals of interfaces are named by
symbols and arranged in different symbol tables.
The name of a symbol follows some conventions. For details, see Section "Conventions for the symbols used in the
subroutines (Page 165)".
Symbol table Table name
1 IO_1
2 IO_2
3, 5, 7, 13
6 MANMACH
14 ASUP
15 PLC_sel_PP
16 IS_MCP
17 IS_HMI
18 IS_AUX
19 IS_NCK
20 IS_CHA
21 IS_AX1
22 IS_AX2
23 IS_AX3
24 IS_AX4
27 MD_PLC
28 ALARM
29 NV_MEM
30 SPC_MEM
31 SBR_MEM
32 RESVD1
Commissioning Manual
01/2017
Symbol
ONE
ZERO
Symbol
NULL_b
NULL_B
NULL_W
NULL_DW
Descriptions
Module I/O are defined by the manufacturer
Distributed I/O are defined by the manufacturer
Reserved for the manufacturer
JOG function
ASUP function
PLC selects part programs
Signals from/to the MCP
Signals from/to the HMI
Auxiliary functions from the NCK
Signals from/to the NCK
Signals from/to the channel
Signals to/from axis 1
Signals to/from axis 2
Signals to/from axis 3
Signals to/from axis 4
PLC machine data
User alarms
Non-volatile memory
Special memory bit
Global memory used in the sample applications and subroutines
Reserved for the sample applications and subroutines
Address
SM0.0
M251.0
Address
M255.7
M255
M254
M252
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