Siemens SIMATIC NET SPC 4-2 LF Manual page 23

Address Name
IND-WP-
00H
PRE
01H IND-WP
02H IND-RD
03H FDL-Ident-
Ptr
04H TS-ADR-
REG
05H SAP-MAX
06H AQUI-ADR
07H GRP-BYTE
08H..17H Internal
work cells
Table 4-4 Assignment of the RAM Parameter Block
PROFIBUS Controller SPC 4®-2 LF
C79000-G8976-C157-3
Access
The write pointer for indication preprocessing points to the
RD/WR
next free segment that follows the last request frame
received even when no indication "IND" has been
received. The IND-WP-PRE pointer allows a fast slave
reaction (for example for PROFIBUS DP). The IND-WP-
PRE pointer is set to the next free segment boundary
immediately after receiving a request frame correctly
(even before a response frame is sent). At the same time,
the "IND-PRE" interrupt is generated.
This pointer must not be changed by the FLC.
RD/WR Write pointer of the indication queue pointing to the next
free segment following the last indicated request frame.
With each "IND" indication interrupt, IND-WP is set to a
new segment boundary by the SPC 4-2. This pointer must
not be changed by the FLC.
RD/WR The read pointer of the indication queue is also a segment
address and is managed by the FLC.
RD/WR Pointer to the Ident buffer
RD/WR Contains the node address
PROFIBUS PA
0 ... 119
120..124
125
126
127
PROFIBUS DP
0 ... 125
126
127
RD/WR The highest SAP list number is set
RD/WR Station address of the valid constant bus cycle time
master (exists only in SPC 4-2 mode, otherwise a write
violation interrupt is generated in response to write
access)
RD/WR Group selection byte for clock synchronization (exists only
in SPC 4-2 mode, otherwise a write violation interrupt is
generated in response to write access)
The following cells must not be overwritten (write-violation
interrupt)
Memory Assignment
Meaning
Normal node
Temporary node (for example handheld)
Default address for temporary nodes
Default address for permanent nodes
Broadcast/multicast
Normal node (recommended for slave:
3..125)
Default address for address assignment
Broadcast/multicast
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