VEGA VEGACOM 557 Profibus FMS User Manual

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VEGACOM 557 Profibus FMS

Setup

PROFIBUS FMS services

From the point of view of the application process (S5 program), the communication system
represents a group of services, the so-called FMS services. Each slave must provide duty
services or can provide additional optional services.

VEGACOM 557 PROFIBUS supports the following services:
- duty services: Initiate, Abort, Reject, Status, Identify, Get OV short form
- optional FMS services: Read, Write, Get OV long form

After switching on the supply voltage, the master sends the initiate service to the slave. Only
then can the communication objects can be read out. For reading in measured values, the
read service is required. In the S5 program, a reading order is passed to the CP with the
functional component FB244, which also uses the read service.

Connection attributes

Defined connection

In planning, the defined connection must be chosen. The communication partners CP5431
(Master) and VEGACOM 557 PROFIBUS (Slave) are permanently defined and must not be
modified. They are in a Master/Slave communication relationship. There is no entry necessary
for the CP parameter setting.

Acyclical data traffic

The various communication objects (here individual measured values or measured value
blocks) are sporadically called by request of the application process via the connection. The
Master/Slave connection for acyclical data traffic must be set in the CP parameters (see FMS
planning, connection type MSAZ).

Communication relationship list (KBL)

From the user’s point of view, the communication with the application processes of the commu-
nication partners is done via logical channels. These logical channels are defined in the KBL
during the planning phase. The KBL is entered during the FMS planning, in which the connec-
tion attribute is permanently set (internally) to defined connection (D).

Example entry of a KBL on the PROFIBUS master with VEGACOM 557 PROFIBUS as commu-
nication partner:

SSAP

TYPE

ATTR

RADR

RSAP

MSAZ

…

KR:

Communication reference

SSAP: own LSAP (of CP5431)
TYPE: Connection type/attribute
RADR: Partner address (Slave), VEGACOM 557 PROFIBUS
RSAP: Partner LSAP (Slave), VEGACOM 557 PROFIBUS