Siemens CP 243-1 IT, Техническое руководство

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03/03 Configuration
CP 243-1 IT
J31069-D0429-U001-A0-7618
75
The structure of the NDB is shown in the following table. The identifiers for
read/write jobs are represented by the letters n, m, p = 0, ..., 31 and the channel
identifiers with the letters r = 0, ...,7.
Byte Offset in
Variable Memory
Name Description Data
Format
Header
128-129 NDB_LENGTH Specifies the length of the NDB 2 bytes, hex
Entries for the first client
130 COM_CH0_ID Identifier of the first client channel 1 byte, hex
131 COM_CH0_OFF Specifies the offset to the first communication
block (COM0) 1 byte, hex
132 COM_CH0_LEN0 Specifies the length of the first communica-
tion block (COM0) 1 byte, hex
... n bytes
n+132 COM_CH0_LENn Specifies the length of the COMn structure 1 byte, hex
n+5 COM_CH0_0 COM0 structure for read/write job 0 for first
client channel
"<op>=<cnt>,<local_buffer>,<remote_buffer>"
(For a description, see Table 10) ASCII
... ... ... ASCII
∑
−
=
+
+
1
0
_ 0 _
5
n
i
LENi CH COM
n
COM_CH0_n
COMn structure for read/write job n for first
client channel
"<op>=<cnt>,<local_buffer>,<remote_buffer>"
(For a description, see Table 10) ASCII
Entries for the second client channel
... COM_CH1_ID Identifier of the second client channel 1 byte, hex
... COM_CH1_OFF 1 byte, hex
... COM_CH1_LEN0 1 byte, hex
... ... 1 byte, hex
... COM_CH1_LENm 1 byte, hex
... COM_CH1_0 ASCII
... ... ASCII
... COM_CH1_m ASCII
... ... (up to 8 channels)
Entries for the rth client channel
... COM_CHr_ID Identifier of the last client channel 1 byte, hex
... COM_CHr_OFF 1 byte, hex
... COM_CHr_LEN0 1 byte, hex
... ... 1 byte, hex
... COM_CHr_LENp 1 byte, hex
... COM_CHr_0 ASCII