Detailed description
2.2 Functions
Basic logic functions: Various NC/PLC interface signals and functions (A2)
34
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
2.2.4
Read/write PLC variable
High-speed data channel
For highspeed exchange of information between the PLC and NC, a memory area is
reserved in the communications buffer on these modules (dualport RAM). Variables of any
type (I/O, DB, DW, flags) may be exchanged within this memory area.
The PLC accesses this memory using 'Function Calls' (FC) while the NCK uses '$ variables'.
Organization of memory area
The user's programming engineer (NCK and PLC) is responsible for organizing (structuring)
this memory area.
Every storage position in the memory can be addressed provided that the limit is selected
according to the appropriate data format (i.e., a DWORD for a 4byte limit, a WORD for a 2-
byte limit, etc.).
The memory is accessed via the data type and the position offset within the memory area.
Access from NC
To allow the NC to access PLC variables (from a part program) quickly, $ variables are
provided in the NCK. The PLC uses a function call (FC) to read and write $ variables. Data
are transferred to and from the NCK immediately.
$ variables can be accessed (by the NCK) during preprocessing and in synchronized
actions.
Data type information is determined by the $ variable data type, the position index is
specified as an array index (in bytes).
The following $ variables are available:
$A_DBB
Data byte (8 bits)
$A_DBW
Data word (16 bits)
$A_DBD
Data double word (32 bits)
$A_DBR
Real data (32 bits)
Ranges of values
$A_DBB(n)
<= x <= 255
$A_DBW(n)
-32768 <= x <= 3276
$A_DBD(n)
-2147483648 <= x <= 2147483647
Содержание SINUMERIK 840D sl
Страница 282: ...Index Basic logic functions Acceleration B2 64 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 286: ...Table of contents Basic logic functions Diagnostic tools D1 4 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 328: ...Constraints Basic logic functions Diagnostic tools D1 46 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 330: ...Examples Basic logic functions Diagnostic tools D1 48 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 340: ...Table of contents Basic logic functions Travel to fixed stop F1 4 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 342: ...Brief Description Basic logic functions Travel to fixed stop F1 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 382: ...Supplementary conditions Basic logic functions Travel to fixed stop F1 46 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 388: ...Basic logic functions Travel to fixed stop F1 Function Manual 11 2006 6FC5397 0BP10 2BA0 52 ...
Страница 790: ...Table of contents Basic logic functions Axes coordinate systems frames K2 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 946: ...Table of contents Basic logic functions Emergency Stop N2 4 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 948: ...Brief Description Basic logic functions Emergency Stop N2 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 956: ...Restrictions Basic logic functions Emergency Stop N2 14 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 958: ...Examples Basic logic functions Emergency Stop N2 16 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 962: ...Index Basic logic functions Emergency Stop N2 20 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 966: ...Table of contents Basic logic functions Transverse axes P1 4 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 978: ...Supplementary conditions Basic logic functions Transverse axes P1 16 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 980: ...Examples Basic logic functions Transverse axes P1 18 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 982: ...Data lists 5 1 Machine data Basic logic functions Transverse axes P1 20 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 984: ...Index Basic logic functions Transverse axes P1 22 Function Manual 11 2006 6FC5397 0BP10 2BA0 Work offset external 13 ...
Страница 990: ...Table of contents Basic logic functions PLC Basic program powerline P3 pl 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1268: ...Supplementary conditions Basic logic functions PLC Basic program powerline P3 pl 284 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1270: ...Examples Basic logic functions PLC Basic program powerline P3 pl 286 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1280: ...Table of contents Basic logic functions PLC basic program solution line P3 sl 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1542: ...Examples Basic logic functions PLC basic program solution line P3 sl 268 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1604: ...Examples Basic logic functions Reference Point Approach R1 58 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1616: ...Brief Description Basic logic functions Spindles S1 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1703: ...Basic logic functions Spindles S1 Function Manual 11 2006 6FC5397 0BP10 2BA0 93 Constraints 3 No supplementary conditions apply ...
Страница 1704: ...Constraints Basic logic functions Spindles S1 94 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1716: ...Index Basic logic functions Spindles S1 106 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1776: ...Detailed description 2 3 Feedrate control Basic logic functions Feeds V1 60 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1786: ...Data lists 5 3 Signals Basic logic functions Feeds V1 70 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1794: ...Table of contents Basic logic functions Tool Offset W1 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1798: ...Short description Basic logic functions Tool Offset W1 10 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1992: ...Data lists 5 3 Signals Basic logic functions Tool Offset W1 204 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 1996: ...Index Basic logic functions Tool Offset W1 208 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 2002: ...Brief description Basic logic functions NC PLC interface signals Z1 6 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 2150: ...Table of contents Basic logic functions Appendix 4 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...
Страница 2184: ...Glossary Basic logic functions Appendix 38 Function Manual 11 2006 6FC5397 0BP10 2BA0 ...