Technical data

Communication SFCs for Non-Configured S7 Connections
System Software for S7-300/400 System and Standard Functions - Volume 2/2
22-20 A5E00739858-01
Parameter Declaration Data Type Memory Area Description
RD OUTPUT ANY I, Q, M, D Reference to the receive area (receive data
area). The following data types are allowed:
BOOL, BYTE, CHAR, WORD, INT, DWORD,
DINT, REAL, DATE, TOD, TIME,S5_TIME,
DATE_AND_TIME
as well as arrays of these data types except
for BOOL.
The receive area RD must be at least as long
as the read VAR_ADDR at the
communication partner. The data types of
RD and VAR_ADDR must also match.
The maximum length of the receive area is 94
bytes.
Changing to the STOP Mode
If the CPU changes to the STOP mode, the connection established by SFC 72
"I_GET" is terminated. Whether or not the received data located in a buffer of the
operating system are lost depends on the type of restart performed:
• Following a hot restart (not on the S7-300 and the S7-400H), the data are
copied to the area defined by RD.
• Following a warm or cold restart, the data are discarded.
Communication Partner Changes to the STOP Mode
If the CPU of the communication partner changes to the STOP mode, this does not
affect the data transfer with SFC 72 "I_GET." The data can also be read with the
partner in the STOP mode.
Data Consistency
The data are received in a consistent state.
Error Information
See Error Information of the Communication SFCs for Non-Configured S7
Connections and Evaluating Errors with Output Parameter RET_VAL