Glossary
Windows Automation Center, WinAC Slot Version 4.0
Hardware Installation and Operating Manual, Edition 02/2006, A5E00273194-02
181
STEP 7 user program:
Application program created with STEP 7 and downloaded to the controller
forexecution. It includes all organization blocks (such as OB 1 or OB 35) and the
other logic blocksthat they call, including functions (FCs), system functions (SFCs),
function blocks (FBs), andsystem function blocks (SFBs).
System function (SFC):
Preprogrammed function that is integrated as a part of the operating system ofthe
controller and can be accessed in the STEP 7 user program, when necessary.
System function block (SFB):
Function block that is integrated as a part of the operating system of thecontroller
and is not downloaded as part of the STEP 7 user program. Like a function block
(FB),an SFB is a block "with memory." You must also create an instance data block
(DB) for the SFB. The instance DB is then downloaded to controller as part of the
STEP 7 user program.
System memory:
The system memory is integrated on the CPU and implemented as RAM.
Thesystem memory includes the operand areas (for example, timers,
counters,memory markers, etc.) as well as the data areas (for example,
communicationbuffers) required internally by the -> operating system.
Time synchronization:
The ability to broadcast a system standard time from a single source to all
deviceswithin the system so that they may set their own clocks to the standard
time.
Time synchronization service:
Software component of WinAC RTX that provides the capability tosynchronize time
between components in the PC Station. (See the documentation for the
WinACTime Synchronization Service.)
Timers:
-> Timers
Transmission rate:
Rate of data transfer (bps).
Ungrounded:
Without galvanic connection to ground
