Siemens SITRANS FC410, Руководство по эксплуатации, Страница: 156 / 160

Glossary
FC410 with Modbus
154
Operating Instructions, 02/2016, A5E33120874-AC
Modbus address
Throughout this document the following notation is used to address Modbus RTU registers:
4: 1234: Holding register 1234 (addressed in messages by 1233)
4: 54321: Holding register 54321 (addressed in messages by 54320)
34567: The address of a holding register as specified in a message
Modbus master
A Modbus master is a Modbus device which is able to access data in one or more connected
Modbus slaves.
Modbus slave
A Modbus slave is a Modbus device which is able to respond to requests from a single
Modbus master.
NAMUR
Normenarbeitsgemeinschaft für Meß- und Regeltechnik in der Chemischen Industrie
(NAMUR). NAMUR is a group representing the interests of the chemical industry which
create standards for instrumentation and electrical devices used in industrial plants.
PED
The Pressure Equipment Directive (97/23/EC) is the legislative framework on European level
for equipment subject to a pressure hazard. It was adopted by the European Parliament and
the European Council in May 1997 and has been obligatory throughout the European Union
since May 2002.
Zero point adjustment
In order to measure accurately with a measuring instrument it is important that zero and gain
have been calibrated. All Coriolis sensors are calibrated before they are sent out to
customers. However, Coriolis sensors are very sensitive, and several factors might move the
zero point, for example installation, pressure, temperature and even very small vibrations
coming from the process. All these factors are customer specific and can’t be simulated at
the factory. Therefore Siemens recommends to carry out a zero point adjustment before use.