Communication
6.6 Communication via USS
Control Units CU240S
182
Operating Instructions, 07/2008 - FW 3.2, A5E00766042B AD
6.6.6
Timeouts and other errors
Telegram Timeouts
For the timeout monitoring, the character run time is important:
Table 6-41 Character run time
Baudrate in bit/s Transfer time per character (= 11 bit) Transfer time per bit Character run time
9600
1.146 ms
104.170 us
1.146 ms
19200
0.573 ms
52.084 us
0.573 ms
38400
0.286 ms
26.042 us
0.286 ms
115200
0.059 ms
5.340 us
0.059 ms
The following figure shows the meaning of the "residual run time":
: : :
: : :
67;
/*(
$'5
Q
%&&
67;
/*(
$'5
Q
%&&
&KDUDFWHUGHOD\WLPH
&KDUDFWHUUXQWLPH
0D[LPXPWHOHJUDPUHVLGXDOUXQWLPH
Residual run time
(compressed telegram)
50 % of the compressed
WHOHJUDPUHVLGXDOUXQWLPH
Figure 6-19 Residual Run Time and Character Delay Time
The character delay time can be zero and must be smaller than the start delay!
The following figure shows the various delays and transmission times:
: : :
: : :
: : :
: : :
67; /*( $'5
Q
%&&
67; /*( $'5
%&&
67; /*(
%&&
Q
6WDUW'HOD\
6WDUW'HOD\
5HVSRQVH'HOD\
0DVWHU5HTXHVW
0DVWHU5HTXHVW
6ODYH5HVSRQVH
Figure 6-20 Start Delay and Response Delay
