Communication
9.5 Communication using USS
Function Manual
Function Manual, 01/2011, 6SL3097-4AB10-0BP3
651
9.5.7 Time-out and other errors
Telegram timeouts
The character runtime is important for timeout monitoring:
Table 9- 50 Character runtime
Baud rate in
bits/s
Transmission time per character (=
11 bits)
Transmission time
per bit
Character runtime
9600 1.146 ms 104.170 μs 1.146 ms
19200 0.573 ms 52.084 μs 0.573 ms
38400 0.286 ms 26.042 μs 0.286 ms
115200 0.059 ms 5.340 μs 0.059 ms
The figure below shows the meaning of "Residual runtime":
: : :
: : :
67; /*( $'5 Q %&&
67; /*( $'5 Q %&&
&KDUDFWHUGHOD\WLPH &KDUDFWHUUXQWLPH
0D[LPXPUHPDLQLQJWHOHJUDPUXQWLPH
Residual runtime
(compressed telegram)
50% of compressed
telegram residual runtime
Figure 9-53 Residual runtime and character delay time
The character delay time can be zero, but it must always be lower than the start delay time.
The figure below shows the different delay times and transmission times:
: : :
: : :
: : :
: : :
6WDUWGHOD\
6WDUWGHOD\
5HVSRQVHGHOD\
5HTXHVWIURPPDVWHU 5HTXHVWIURP
WKHPDVWHU
6ODYHUHVSRQVH
67; /*( $'5 Q %&&
67; /*( $'5 %&&
67; /*(
%&&
Q
Figure 9-54 Start delay and response delay