Endress+Hauser Proline Promag 51, Руководство по эксплуатации

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Proline Promag 51 5 Operation
Hauser 57
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Note!
In custody transfer mode, error messages are always issued via the local display and, as an option,
via the outputs. The error message can be sent via the status output, current output or frequency
output to the subsequent system units.
5.4 Communication
In addition to local operation, the measuring device can be configured and measured values can be
obtained by means of the HART protocol. Digital communication takes place using the 4–20 mA
current output HART (see Page 46).
The HART protocol allows the transfer of measuring and device data between the HART master
and the field devices for configuration and diagnostics purposes. The HART master, e.g. a handheld
terminal or PC-based operating programs (such as ToF Tool - Fieldtool Package), require device
description (DD) files which are used to access all the information in a HART device.
Information is exclusively transferred using so-called “commands”. There are three different
command groups:
Universal commands:
All HART device support and use universal commands. The following functionalities are linked to
them:
• Identify HART devices
• Reading digital measured values (volume flow, totalizer, etc.)
Common practice commands:
Common practice commands offer functions which are supported and can be executed by most
but not all field devices.
Device-specific commands:
These commands allow access to device-specific functions which are not HART standard. Such
commands access individual field device information, amongst other things, such as empty/full pipe
adjustment values, low flow cutoff settings, etc.
!
Note!
Promag 51 has access to all three command classes. On Page 61, you will find a list with all the
supported “Universal Commands” and “Common Practice Commands”.