Communication via SIKONETZ5
AG05
Date: 15.06.2016 Art. No. 85677 Mod. status 139/16 Page 49 of 64
10.3.7 Check sum
For checking error-free data transfer, a check sum is formed at the end of the telegram. The
check sum is the exclusive-OR-link of bytes 1 – 9:
Check sum [Byte10] =
[Byte1] XOR [Byte2] XOR [Byte3] XOR [Byte4] XOR [Byte5] XOR [Byte6] XOR [Byte7] XOR
[Byte8] XOR [Byte9]
The following applies for checking the telegram received:
[Byte1] XOR [Byte2] XOR [Byte3] XOR [Byte4] XOR [Byte5] XOR [Byte6] XOR [Byte7] XOR
[Byte8] XOR [Byte9] XOR [Byte 10] = 0
With a result unequal 0 a transmission error is to be assumed.
10.4 Synchronization
Byte/telegram synchronization is via "Timeout". The intervals between the individual bytes of
a telegram must not exceed the value of 10 ms. If an addressed device does not respond, the
master must not send another telegram earlier than after 30 ms.
10.5 Error telegram
Illegal entries are replied with an error telegram.
An error telegram consists of parameter address 0xFD and an error code.
The error code is in the data section of the reply telegram. The error code is divided in two
bytes. Code 1 describes the error proper and code 2 contains additional information if
available.
In the following example an attempt was made at writing a value of 1000 to the v-Pos
parameter address.
However, a maximum value of only 30 is admissible for this parameter.
Telegram from master to slave
Reply telegram from slave
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