S5-95U, Second Serial Interface
Computer Link with 3964(R) Transmission Protocol
Error messages in the
”
receive
”
coordination byte
In a receive request, various errors may occur, which are assigned different priorities by the
computer link. The KBE always contains the error which has the highest priority in the last receive
attempt. In Table 3-2, the highest priority has the value 0 and the lowest is assigned the value 6.
Table 3-2 Error Messages in the ”Receive” Coordination Byte
*
DLE and ETX are control characters for connection buildup and cleardown (DLE = Data Link Escape, ETX = End of
Text). The procedure automatically duplicates this data item to make sure that a data item having the same code as a
control character (DLE in this case), is recognized as data by the procedure.
The control character sequence DLE - ETX is fixed to ensure a proper connection cleardown.
**
STX is the control character for extablishing the link with the other node (STX = Start of Text).
Priority
Assignment
Meaning
Response
Parity error
Data rejected
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
03
H
07
H
Input buffer full
09
H
0B
H
0F
H
13
H
Too many frames received
(more than 100 frames)
Frame longer than receive mailbox
Receive mailbox not available
DT character delay time error
Data valid but the following
frames have been rejected
Data rejected
BWT block wait time error
15
H
17
H
Check sum error
1B
H
Break
05
H
Frame with length 0
0D
H
DLE was not duplicated or no ETX
after DLE*
11
H
STX error; handshaking did not start
with STX **
5
6
2
2
0
3
0
4
2
5
1
3
The position of the coordination bytes is to be parameterized in DB1 ( Section 3.4).
EWA 4NEB 812 6095-02
3-9