Glossary
Glossary - SIMATIC D7-SYS G-7
Edition 12.2004
D
Connectors, which are used to jumper empty slots at the backplane bus
of a SIMADYN D subrack, where a module is not inserted.
The slots which require daisy-chain connectors can be seen in the
detailed view of HWConfig.
Data blocks are interfaces in the user program and are used to address
variables. Data blocks do not require any additional memory space.
There are
• instance data blocks, which are used to transfer data to WinCC, and
• data blocks, which include a user data area, to realize
communications with SIMATIC-OPs.
For interconnections and $ signals between different cyclic tasks, D7-
SYS guarantees that all of the transferred data are consistent. This
means that data, transferred from a task Ti, are taken from the same
computation cycle of this task.
If a signal is to be transferred without deadtime, it is possible to bypass
data consistency ($ signal, "Fast" type or by interconnecting with a
pseudocomment DATX).
Also refer to: Process image
Permanently structured memory medium (e.g. dual port RAM), which two
coupling partners can access to transfer data.
The structure defines how the data interface is configured (e.g. where
general initialization data are deposited, the data memory size and what
is still available). The data interface structure is the same for all
couplings. The contents of the data interface structure are of no
importance for the user, because when configuring couplings, memory
areas do not have to be explicitly addressed.
Configurable data transfer mechanism for senders and receivers.
Handshake, refresh, select and multiple modi can be selected. Senders
and receivers must have the same configured data transmission mode;
otherwise, they will not be able to synchronize with one another and
exchange data.
Also refer to: Channel
Each I/O of a block is assigned a particular data type. It defines the value
range, resolution, display and interpretation of values at this input or
output.
"BOOL" defines, for example, a binary variable, "INT" defines a 16-bit
fixed-point variable.
If a connected block input is to receive its values from a connected
output, bypassing the data consistency mechanisms, then it must be
marked with a pseudocomment "@DATX".
Also refer to: Data consistency
When synchronizing the basic clock, the delay time between the initiating
process interruptand when the cyclic tasks is started. This time can be
configured.
Daisy-chain
connector
Data block (DB)
Data consistency
Data interface
Data transfer mode
Data type
DATX
Delay time