HIMA HIQuad H41X, Системное руководство

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System Programming
HI 803 211 E Rev. 1.01.00 Page 75 of 110
6.1.3.4 Calculating the Maximum Duration of Configuration Connections [ms]
If communication is not completely processed within a CPU cycle, it is resumed in the next
following CPU cycle at the interruption point. This slows down communication, but it also
ensures that all connections to external partners are processed equally and completely.
The value of Max. Duration of Configuration Connections [ms] is included in the watchdog time
and must be selected so that the cyclic processor module tasks can be executed in the
remaining time.
The volume of the configuration data to be communicated must be observed. This depends on
the number of configured remote I/Os, the existing connections to PADTs and the system
modules with an Ethernet interface.
A temporary setting for the F-CPU 01 module can be calculated as follows:
t
Config
= n
Com
+ n
PADT
+ n
RIO
* 0.25 ms + 4 ms + 4*(t
Latency
* 2 + 0.8)
t
Config
System parameter Max. Duration of Configuration Connections [ms]
n
COM
Number of modules with Ethernet interfaces (CPU, COM)
n
RIO
Number of configured remote I/Os
n
PADT
Maximum number of PADT connections = 5
t
Latency
To obtain the value in ms, divide the Maximum System Bus Latency [µs] by
1000.
If t
Config
is less than 6 ms, the value must be set to 6 ms.
The calculated value t
Config
must be compared with the real value derived from the online
statistics of the Control Panel. The real value depends on the system structure.
If the value calculated for t
Config
is greater than the real value, the remaining time will not be used
for other cyclic tasks, such as the adoption of an additional CPU for redundancy operation. The
remaining time is not included in the cyclic reserve time.
i
If the real value is greater than the value calculated for t
Config
, the parameter located in the
resource properties must be corrected (observe the watchdog time) and loaded into the
controller by performing a download or reload. Alternatively, a direct online change is also
possible. Not correcting the value causes the system handling via PADT to slow down.