Balluff BTL5-T110 Technische Beschreibung Seite 67

BTL5-T110...
Configuration and Profibus Connection –
Transducer Class 3/4
6 Startup (cont.)
6.3 Programming acyclic
services (DP-V1)
6.3.1 Introduction to DP-V1
Profibus offers both cyclic data
communication and acyclic
services, which are described in
DP-V1. The telegram structure for
DP-V1 is modular. The data area
addressed as "Slot Number" and
as "Index". The "Slot Number
indicates the module, and the In-
dex addresses a data record
within this module. The parameters
in the transducer are all accessed
through Slot 0 Index 47, except for
➥ ➥ ➥ ➥ ➥ page 45),
the I&M parameters (
which are accessed through Slot 0
Index 255.
6.3.1.1 Services
The services are divided into Ma-
ster Class 1-/ Slave functions
(MSAC_C1) and Master Class 2-/
Slave Functions (MSAC_C2).
The following services are
implemented in the transducer:
Fig. 6-7: Principle communication scheme for acyclic data exchange (Example (Read))
20
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Function Master-SAP Slave-SAP
MSAC_C1 51
MSAC_C2 50
MSAC_C2 50
Table 6-1: SAPs assignment for the DP-V1 cyclic data communication
MSAC_C1 (Master-Slave acyclic
communication, Class 1)
– Read data record of a slave
(Read)
– Write to data record of a slave
(Write)
MSAC_C2 (Master-Slave acyclic
communication, Class 2)
– Initiate (open connection to
slave)
– Read data record of a slave
(Read)
– Write to data record of a slave
(Write)
– Abort (close connection to slave)
The SAPs newly assigned for
DP-V1 are different for Class 1
masters and Class 2 masters. In
Services
51 Read, Write
49 Initiate.req
0...48 Abort, Read, Write
the following table you are shown
the assignments of the individual
SAPs to the services.
Since data communication in
MSAC_C1 communication is
monitored in cyclic data
communication, the opening and
closing of the connection using
Initiate/Abort as with MSAC_C2
connections is not necessary.
Errors in cyclic data
communication affect acyclic data
communication and vice-versa.
After a Class 1 master has enabled
extended node in the „Set_Prm-
Telegram", it can communicate
with a slave over SAP 51 in
„Data_Exchange". After
„Leave_Master" SAP 51 is again
deactivated. Note that SAP 50 and
51 are enabled only in data
exchange.