MD‑SI‑DP1 Communication
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● LADDR: Starting address configured in the Q block of the module, which must
be in hexadecimal format.
● RET_VAL: Return value. If an error occurs during function activation, the return
value contains an error code. If no error occurs, 0 is returned.
● RECORD: Source area of the user data to be written. Its length must be
consistent with the length of the module configuration selected in STEP 7. Only
the byte data type is allowed.
For both SFC14 and SFC15, the addresses must be in hexadecimal format
converted from the I and Q starting addresses (in this example, the address is 520,
which is H208 in hexadecimal format). The length of RECORD must be consistent
with the BYTE length of the PPO type PZD (in this example, PPO2 is used, which
includes six PZDs, that is, a total of 12 bytes).
8.7.5 Performing Aperiodic Read/Write Operations on the AC Drive Slave
To perform aperiodic read and write operations on the AC drive PROFIBUS DP slave,
Siemen's system function modules SFB52 (for reading) and SFB53 (for writing) are
required. Create an organization block in the program, and add relevant function
blocks and programs in the organization block.