Siemens SIMATIC S5-115U, User Manual, Page: 437 / 676

S5-115U Manual Communications Capabilities
The following points apply to the assignment of DB1:
•
The parameter data to be interpreted must always be preceded by interprocessor commu-
nication flag definitions.
• You can enter interprocessor communication flag areas in any order.
• You can enter the byte numbers for an area in any order.
• The CPU accepts the entries in DB1 only during Manual Restart. You must therefore execute a
program restart each time you modify DB1.
Signal Exchange with a CP
Set jumpers on the CP to enable the area required as interprocessor communication flag bytes.
The jumpers divide the area between bytes 0 and 255 into eight blocks of 32 bytes each.
Normally the entire interprocessor communication flag area is enabled. Setting is necessary only
when you use several CPs with interprocessor communication flags.
Specify the desired interprocessor communication flags in DB1. The bytes must be in the set area.
You can choose any bytes from this area. However, use only as many bytes as necessary to keep
the transfer time as short as possible.
Example:
20 interprocessor communication flag bytes are needed for a signal exchange:
•
14 bytes to transfer information to the CP
• 6 bytes to fetch information from the CP
The jumper setting on the CP enables the area between byte 128 and byte 159.
The interprocessor communication flags are defined in DB1 as follows:
Outputs:
FY 128 to 141
Inputs: FY 142 to 147
The words in the DB are assigned as follows:
DW 0 : KH = 4D41
1 : KH = 534B Header ID
2 : KH = 3031
DW 3 : KH = CE00
4 : KF = +142
5 : KF = +143
6 : KF = +144 Interprocessor communication input
. flags
.
.
DW 9 : KF = +147
DW 10 : KH = CA00
11 : KF = +128
12 : KF = +129 Interprocessor communication output
. . . flags
. . .
. . .
DW 24 KF = +141
DW 25 : KH = EEEE End ID
EWA 4NEB 811 6130-02b
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