Plc Programming - Siemens Sinumerik 802D sl Instruction Manual

Starting Up the PLC
11.4

PLC programming

11.4 PLC programming
The PLC user program is created using the PLC 802 Programming Tool.
The handling of this tool for an S7-200 is described in the documentation "SIMATIC S7-200
Automation System Manual". The PLC 802 Programming Tool constitutes a subset of this
documentation.
Compared to the S7-200 MicroWin base system, the following is to be observed:
S The user program can only be programmed in ladder diagram.
S Only a subset of the S7-200 programming language is supported.
S The compilation of the user program is performed offline on a PG/PC or automatically
when downloading into the control system.
S The project can be loaded into the control system (download).
S It is also possible to load the project from the control system (upload).
S Indirect data addressing is not possible. Thus, no programming errors will occur during
the runtime.
S The user must manage the data and process information type-specifically.
For all accesses to the data, it is imperative to use consistently the agreed data type.
Example:
Information 1
Information 2
User data
Memory double-word
Memory byte
S Furthermore, the alignment towards certain memory addresses is dependent on the data
type. This alignment is performed towards bus addresses which can be divided by the
byte length of the data type without remainder.
BOOL and BYTE can start at any byte address (0, 1, 2, 3, ...),
WORD and INT must start at an even byte address (0, 2, 4, 6, ...) and
DWORD, DINT, REAL must start at a byte address which can be divided by 4
(0, 4, 8, 12, ...).
Example:
Memory bits
Memory bytes
Memory word
Memory double words
Table 11-2 PLC data types permitted in the control system
Data type Size
BOOL 1 Bit
BYTE 1 byte
11-170
T value
Override
MB0.1,MB3.5
MB0,MB1,MB2
MW0,MW2,MW4
MW3, MW5 ... are not permissible
MD0,MD4,MD8
MD1,MD2,MD3, MD5 ... are not permissible
Address Range for logical operations
alignment
1 0.1
1 00 ... FF
Memory size DInt (32-bit)
Memory size Byte (8-bit)
MD0 DInt (information 1)
MB4 Byte (information 2)
–
0 ... +255
SINUMERIK 802D sl Instruction Manual (BA), 05/2005 Edition
Range for arithmetic operations
6FC5 397-0CP10-1BA0