Siemens 6DR50 Series Operating Instructions Manual page 289

Pressure chamber
Pneumatic actuators are available in single and double-acting versions. In a single-acting
version, only one pressure chamber is ventilated and depressurized. The pressure
developed works against a spring. In a double-acting version, two pressure chambers work
against each other. Ventilating the volume of one chamber simultaneously depressurizes the
volume of the other.
Process device manager
PDM is a Siemens software package for project planning, parameter assignment,
commissioning and maintenance of network configuration and field devices. Part of SIMATIC
Step7. Is used for configuration and diagnostics.
PROFIBUS
PROFIBUS stands for process fieldbus. PROFIBUS is a vendor-independent standard for
networking field devices (e.g. PLCs, actuators, final control elements, and sensors).
PROFIBUS is compatible with protocols such as DP (decentralized peripherals), FMS
(fieldbus message specification) and PA (process automation).
PROFIBUS PA
PA is an abbreviation of process automation. PROFIBUS PA is used in process engineering.
This fieldbus is used to control the measuring devices using a process control system. This
version of PROFIBUS is suitable for hazardous areas of zones 0 and 1. Only a weak current
flows through an intrinsically safe circuit in the bus cables, and hence sparks are not
generated even in case of a fault.
PA enhances PROFIBUS DP with an intrinsically safe transmission technique compliant with
the international standard IEC 61158-2.
Protection level
● ia: Protection level. Electric equipment operating fault-free, and with existence of two
countable errors.
● ib: Protection level. Electric equipment operating fault-free, and with existence of one
countable error.
● ic: Protection level. Electrical equipment is not able to cause an ignition when operating
fault-free.
Protocols
Protocols contain information about data formats, time sequences and error handling when
exchanging data between computers.
A protocol is a convention about establishing, monitoring and terminating a connection.
Different protocols are required for a data connection. Protocols can be assigned to every
layer of the reference model. Transport protocols are used for the lower four layers of the
reference mode and higher protocols are used for control, data provision and application.
SIPART PS2 with and without HART
Operating Instructions, 09/2014, A5E00074631-12
Glossary
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