System description - Pilz GmbH & Co.

System environment B basics
System description
Reaction times
Cycle time with external communication
(t ExtCo )
External communication refers to
data exchange in which O-data
leaves the automation system
PSS 4000 and I-data enters the
system (e.g. via Modbus/TCP,
UDP, fieldbuses). External O-data is
sent from the O-data area of a
PSSu system, depending on the
communication mode that is used.
Depending on the communication
mode that is used, external I-data
can be found in the I-data area of a
PSSu system and is read from
there.
In this description, the cycle times
for send and receive are designated
with t ExtCo . Their meaning depends
on the communication mode that is
used:
– Modbus/TCP Client connection:
The cycle time t ExtCo describes
the time the connection Client
takes to start data transfer as
part of each cycle.
The cycle time can be set separately
in PAS4000 for each connection
Client on a PSSu
system; in other words, each
connection Client on a PSSu
system has its own cycle time
t ExtCo . It can either be calculated
automatically it can be configured
by the user (configuration in
PAS4000).
– Modbus/TCP Server connection:
The cycle time t ExtCo describes
the time it takes to read in data
from a Server mapping table on
a PSSu system and transmit requested
data from a Server
mapping table to the connection
Client, as part of each cycle.
The cycle time can be set separately
in PAS4000 for each Server
mapping table on a PSSu
system; in other words, each
Server mapping table on a PSSu
system has its own cycle time
t ExtCo . It can either be calculated
automatically it can be configured
by the user (configuration in
PAS4000).
– Raw UDP communication "Receive
data" and "Send data":
The cycle time t ExtCo describes
the time it takes to read in external
I-data from a UDP connection
and start transmitting data
(external O-data) via a UDP connection
as part of each cycle.
The cycle time can be set separately
in PAS4000 for each UDP
connection on a PSSu system; in
other words, each UDP connection
has its own cycle time t ExtCo .
It can either be calculated automatically
it can be configured by
the user (configuration in
PAS4000).
– PROFIBUS-DP Slave "Receive
data" and "Send data":
The cycle time t ExtCo describes
the time it takes to read in external
I-data from the PROFIBUS-
DP Master and start transmitting
the requested data (external
O-data) as part of each cycle.
The cycle time can be defined in
PAS4000 for each PSSu system,
i.e. each PSSu system has its
own cycle time t ExtCo for data
transfer with PROFIBUS-DP. It
can either be calculated automatically
it can be configured by
the user (configuration in
PAS4000).
Processing rules during data
processing
Funktionsweise_Verarbeitungsregeln bei der Datenverarbeitung
The following applies for data
processing on a PSSu system:
Processing times of modules
The processing times of modules
(t ProcOM and t ProcIM ) are constant.
They are not influenced by the current
task cycle.
Module bus cycle times
The ST module bus and the FS
module bus each have their individual
cycle times. The module bus cycle
time t MBUS always corresponds
to that of the task with the shortest
cycle time, provided that the task
cycle time is less than/equal the
maximum possible cycle time of the
corresponding module bus:
t MBUS = t Task min
Cycle times of tasks
The cycle times of tasks (t Task ) are
constant. They are not influenced
by the current task cycle.
2.1
Pilz GmbH & Co. KG, Felix-Wankel-Straße 2, 73760 Ostfildern, Germany
Telephone: +49 711 3409-0, Telefax: +49 711 3409-133, E-Mail: pilz.gmbh@pilz.de
2011-04
2.1-35