6 Configuration and Settings
6.3 Comments on programming the SIMATIC S7-1200
6.3.2
Configuring the RDREC/WRREC instruction
Table 6-4: RDREC/WRREC – Configuration of the instruction
Parameter
ID
LEN
(for WRREC)
MLEN
(for RDREC)
INDEX
RECORD
SINAMICS G120 DP at S7-1200
Entry-ID: 70155469,
V1.4,
ID has the same function as the LADDR parameter for
DPRD_DAT/DPWR_DAT (see
WRREC the formal parameter ID must be supplied with the smaller of
both system constants, i.e. "Transfer_area_1[DI] in the application
example".
Even if you only wish to use the acyclic services in your communication
with the SINAMICS G120, a cyclic data exchange will be configured by
STEP 7. In this case, however, you can select the "Standard Telegram 1"
frame (default setting) with the smallest data length.
When unfolding the block by clicking on the small triangle, additionally,
the input parameter "LEN" appears for specifying the maximal length of
the data set to be transferred.
Since in this example the data set length is contained in the "RECORD"
parameter, "LEN" needs not be configured. Keep the default value 0.
Maximum length of the data set information to be read in bytes.
Since in this example the data set length is contained in the "RECORD"
parameter as well, "MLEN" needs not be configured. Keep the default
value 0.
Here, the data set to be transferred
must be specified. Enter the value
47 as the actual parameter for
"data set 47".
RECORD of type "VARIANT" is a
pointer with specified length. It
points to data records "record" in
the DBs from chapter 5.2.2. In the
application example, RECORD is
addressed symbolically (see
footnote
10
on page 59).
07/2018
Explanation
Table
6-3). For RDREC as well as for
60