Ob61; Pip (Process Image Partition); Consistency - Datalogic AMT58 Series Manual

OB61

CAUTION
Organization blocks (OBs) form the interface between the CPU operating system and
the user program. The order in which the user program is executed is defined in the
organization blocks.
The synchronization with the user program is maintained through the clocked interrupt
OB61. OB61 is a synchronous cycle interrupt; in other words it is an isochronous event
that is called with the start of every PROFINET cycle. It is synchronous with the Profinet
send clock.

PIP (PROCESS IMAGE PARTITION)

CAUTION

Consistency

PIPs (Process Image Partitions) are used to update the distributed IO device synchro-
nously with the constant bus cycle time clock.
Compared with direct access to the input/output modules, the main advantage of
accessing the process image is that the CPU has a consistent image of the process sig-
nals for the duration of one program cycle. If a signal state on an input module changes
while the program is being executed, the signal state in the process image is retained
until the process image is updated again in the next cycle. The process of repeatedly
scanning an input signal within a user program ensures that consistent input informa-
tion is always available. You define process image partition with TIA PORTAL when you
assign addresses (which input/output addresses of the modules are listed in which pro-
cess-image partition). The process image partition is updated by the user with SFCs.
Figure 9. Process Image Partition
Use of OBs requires both in-depth skills and specific expertise in TIA POR-
TAL programming environment. For detailed information please consult the
TIA PORTAL Programmer's handbook and documentation.
Use of PIPs requires both in-depth skills and specific expertise in TIA POR-
TAL programming environment. For detailed information please consult the
TI PORTAL Programmer's handbook and documentation.
OB61
77
INSTRUCTION MANUAL