INFICON SKY CDGxxxD (Profibus) - Manual (Page 18)

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tira54e1-a (2009-01) CDGxxxD.cp
6 Block Model
Data to the CDGxxxD can be transmitted by means of a number of communication
protocols and corresponding masters. Profibus defines a master class 1 as normal
control unit of the slave (typically a PLC) and a master class 2 as configuration and
service unit. The following communication protocols are defined according to the
Profibus DPV1 standard.
MS0 Cyclic data traffic between master class 1 and slave
MS1 Acyclic data traffic between master class 1 and slave
MS2 Acyclic data traffic between master class 2 and slave
In the CDGxxxD, all functions that are made available by the gauge via Profibus
are organized in blocks. Access to the individual parameters of the blocks is possi-
ble via acyclic services or, for byte, integer and float values, also in cyclic data
traffic via the parameter channel.
The following block types are defined in the CDGxxxD gauge:
Device Block The Device Block contains all data that are required for de-
scribing the device and handling its state (status of Device
State Machine). See chapter 7.
Function Block Application specific values such as pressure values that result
from or can be calculated from the values of the transducer
block are represented in the function blocks.
• Analog Input Function Block (Instance 1, CDG).
See section 8.1.
• Analog Input Function Block (Instance 2, ATM).
See section 8.2.
• OneofN Analog Input Function Block.
See chapter 9.
• Discrete Output Function Block (Relay 1 and Relay 2).
See chapter 10.
• Trip Point Function Block (Relay 1 and Relay 2).
See chapter 11.
Transducer Block The physical, process specific functions or interfaces between
the CDGxxxD and the process are represented in transducer
blocks.
The following transducer blocks are implemented:
• Capacitance Diaphragm Gauge (CDG) Transducer Block.
See section 12.1.
• Atmosphere Pressure Sensor (ATM) Transducer Block
See section 12.2.
6.1 Block types