Siemens SIMATIC NET CP 243-1, Operating Instructions Manual

Page: 73 / 142

Configuration
3.4 Other options when configuring a CP 243-1
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02
73
The structure of the NDB is shown in the following table. The identifiers for read/write
requests are represented by the letters n, m, p = 0, ..., 31 and the channel identifiers by the
letters r = 0, ...,7.
Byte offset in variable
memory Name Description Data format
Header
128-129
Entries for the first client channel
130
COM_CH0_ID 1 byte, hex
131 COM_CH0_OFF 1 byte, hex
132 COM_CH0_LEN0 1 byte, hex
... ... n bytes
n+132 COM_CH0_LENn 1 byte, hex
n+5 COM_CH0_0 ASCII
... ... ASCII
COM_CH0_n 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
... ASCII
COM_CHr_p ASCII