Manual 7XV5655-0BB00
SIEMENS AG
Page 47 of 79
C53000-G1176-C175-3
Optimising Data Transfer
Great emphasis has been placed on compatibility in the design of this device.
Due to the Ethernet, there are, however, some minor restrictions. Data is not
transmitted in bytes to the network. This is done in data blocks via Ethernet.
This might result in minor delays. Block formation function does not directly
affect the application but might help to reduce the network load. Some fine
tuning might be necessary for time-critical applications. This involves the two
timeout parameters ("Total Read Timeout", "Character Distance").
Block Formation for Serial Data before Transmission into the Ethernet
After the first byte has been received, "Total Read Time" starts. After the time
expires, all characters received so far are relayed to the Ethernet. The default
value is 50 ms.
"Character Distance" is the maximum interval between two received
characters. If this is exceeded, all characters received so far are transmitted
into the Ethernet. The default value is 5 ms.
Total read timeout
Total read timeout
Character timeout
Transmission
to PC
Transmission
to PC
Transmission
to PC
No transmission.
Gap is too small.
Transmission because
"Total Timeout" has
expired
Transmission because
the gap between the
characters is larger
than "Char Timeout"
Transmission because
the gap between the
characters is larger
than "Char Timeout"
