Calling Acyclic Services - Siemens DP/AS-Interface Link 20E Manual

Data Exchange Between the DP Master and AS-i Slave
2.4.1

Calling Acyclic Services

DP Master with Acyclic Services
The acyclic services complying with the DP standard DP-V1 for PROFIBUS-DP
allow further jobs for sending output data to the DP slaves or for receiving input
data from the DP slaves in addition to cyclic data transfer.
The acyclic services are used for the following with the DP/AS-i Link 20E:
S Reading/writing analog values
S Command interface (see Chapter 3)
Calls
Table 2-1
read_record
write_record
Call Parameters
Certain parameters must have values assigned to specify the job. The names of
these parameters and the type of parameter setting can vary depending on the
type of the DP master.
The following table provides you with an overview of the parameters according to
the DP-V1 specification and shows examples of how they are mapped in the
parameter assignment of a user program for a SIMATIC S7 CPU and a user
program for a PC/programming device in which the SIMATIC NET programming
interface is used.
56
Call With SIMATIC S7 With the DP programming
SFC 59
SFC 58
interface
dpc*_read
dpc*_write
DP/AS-Interface Link 20E
Release 11/2002
C79000-G8976-C138–04