5 Programming HIMax System
HI 801 001 E Rev. 4.01 Page 54 of 122
Parameter /
Switch
Description
Default
value
Setting for safe
operation
Maximum delay of a message between an I/O module
and the processor module. 0, 100...50 000 µs
Maximum System
Bus Latency [µs]
i
A license is required for setting the maxi-
mum system bus latency to a value > 0.
0 µs
Application-
specific
SILworX
V.2.36.0
The CRC for safeethernet is created as in
SILworX version 2.36.0. This setting is re-
quired for exchanging data with resources
planned with SILworX version 2.36 or pre-
vious versions.
safeethernet CRC
Current
Version
The CRC for safeethernet is created with
the current algorithm
Current
Version
Application-
specific
Table 16: Resource System Parameters
Calculating the Maximum Duration of Configuration Connections [µs]
If communication is not completely processed within a CPU cycle, it is continued in the next
following CPU cycle at the interruption point.
This slows down the process data communication, but it also ensures that all connections
to external partners are processed equally and completely.
For firmware HIMax CPU V3, the value of the maximum duration of configuration
connections in SILworX is set to 6 ms by default. The time required to process
communication with external partners may, however, exceed the default value in a CPU
cycle.
For firmware HIMax CPU V4, the value of the maximum duration of configuration
connections must be set taking the defined watchdog time into account.
Suitable value: Select the value such that the cyclic processor tasks can be executed within
the time resulting from Watchdog Time - Max. Duration of Configuration Connections.
The volume of the process data to be communicated depends on the number of configured
remote I/Os, the existing connections to the PADT and the modules within the system that
have an Ethernet interface.
A first setting can be calculated as follows:
T
Config
= (n
Com
+ n
RIO
+ n
PADT
) * 0.25 ms + 2 ms + 4*T
Latency
, where
T
Config
System parameter Max. Duration of Configuration Connections [ms]
nC
om
Number of modules with Ethernet interfaces {SB, CPU, COM}
n
RIO
Number of configured remote I/Os
n
PADT
maximum number of PADT connections = 5
T
Latency
System parameter Maximum System Bus Latency [µs]
If the calculated time value is less than 6 ms, it is rounded up to 6 ms. The online statistics
can be used to modify the calculated time either later in the resource properties or
immediately online.
i
When generating the code or converting the project, a warning message is displayed in the
PADT if the defined Max. Duration of Configuration Connections is less than the value
resulting from the previous formula.
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