Siemens SIMATIC S5 CP 523 Manual page 161

Communications Mode
Table 7-30. Return Info and Error Flags in the Coordination Byte 'Receive' (CBR)
in "3964(R) Mode"
Bit
7 6 5 4 3 2 1 0
1 XX
*
H
0
03
H
05
H
07
H
09
H
0B
H
0D
H
11
H
13
H
15
H
17
H
1B
H
00
H
* See error message
7-56
Description
Return info for A080
Request accepted
No message frame to fetch
Error flags for A080
H
Parity error
Frame length 0
Receive buffer full
Too many message frames received
Frame too long (256 bytes)
DLE not doubled or no ETX after DLE
STX error, handshaking ON but no STX
Character time-out
Message frame time-out
Checksum error
Break
No errors
H
CP 523
Response
Data rejected
Data rejected
Buffer full,
subsequent message
frames will be rejected
Data rejected
Data rejected
Data rejected
Data rejected
Data rejected
Data rejected
Data rejected
EWA 4NEB 811 6044-02a