Siemens CM 1542-5 Manual page 16

Requirements for use
4.3 Programming
System blocks and sys-
tem functions
SETIO
GETIO_PART
SETIO_PART
D_ACT_DP
DPRD_DAT
DPWR_DAT
RALRM
Refer to the documentation of the program blocks in the online help of STEP 7
Calling program blocks (instructions) for distributed I/O
Several calls are necessary for the instructions of the distributed I/O.
The time required to process the job depends on load, round-trip time and transmission
speed. If these instructions are called in a loop within one cycle, the cycle time could be
exceeded.
Exceptions:
● Only one call is required for the RALRM instruction "receive alarm".
Program blocks for DPV1 (according to the PNO standard)
● Instruction RDREC "Read data record from a DP slave" corresponds to SFC59 in terms
of function
● Instruction WRREC "Write data record to a DP slave" corresponds to SFC58 in terms of
function
● Instruction RALRM "Read interrupt information from a DP slave" - call in an interrupt OB
PNO: PROFIBUS Users Organization
1)
See also
8797900 (http://support.automation.siemens.com/WW/view/en/8797900)
16
Meaning when used with CM
Transferring the process image of a DP standard slave
Reading the process image partition of a DP standard slave
Transferring the process image partition of a standard DP slave
Disable / enable DP slaves
Reading consistent data of a DP standard slave
Writing consistent data of a DP standard slave
Event-driven reading of interrupt information (diagnostics, pull/plug,
hardware interrupt) and DPV1-specific interrupts (update, status, vendor-
specific interrupt)
:
1)
Manual, 11/2014, C79000-G8976-C290-02
CM 1542-5