Configuration
3.4 Other options when configuring a CP 243-1
CP 243-1
74 Operating Instructions, 03/2012, C79000-G8976-C244-02
Byte offset in variable
memory
Name Description Data format
CRC section
The last two bytes of the
NDB
CRC for all NDB bytes
without the CRC section
itself
2 bytes, hex The last two bytes of the
NDB
Structure of the NDB
Name Description Data format
<op> Request type
• Value range:
– "R" for read,
– "W" for write
ASCII
<cnt> Number of bytes to be transferred
• Value range:
– "1" to "212"
ASCII
<local_buffer> Address of the memory area in the
local system
• Value range:
– "VB0" to "VBx", where x is the
max. V address
ASCII
<remote_buffer> Address of the memory area on the
communications partner
• Value range:
– "IB0" to "IBx", where x is the
max. input address (S7-200 /
S7-300 / S7-400)
– "QB0" to "QBx", where x is the
max. output address (S7-200 /
S7-300 / S7-400)
– "MB0" to "MBx", where x is the
max. bit memory address (S7-
200 / S7-300 / S7-400)
– "VB0" to "VBx", where x is the
max. variable address (S7-200)
– "DB0.DBB0" to "DBx.DBBy",
where x is the max DB number,
and y is the highest address in
the relevant data block within
the DB (S7-300 / S7-400)
ASCII
Configuration of the read/write requests