Lufft CHM 15k Nimbus, Руководство пользователя

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Communication RS485 & Ethernet
Revision R09, November 2016 31
8 Communication RS485 & Ethernet
The CHM 15k Nimbus supports two interfaces RS485 (section 8.2) and Ethernet
(section 8.7) to communicate with the instrument. Both have the opportunity to
transfer the measured values and to configure the instrument.
A web-interface is part of the system for the main communication (configura-
tion) over the Ethernet interface. It can be accessed by many web browser inde-
pendent from the operating system.
The web-interface can also be used to download measured data manually,
which are stored in daily NetCDF (section 8.4) files on a build in SD Card. An AFD
(ftp) service (section 8.8) is implemented in the system too, which allows the
transfer of 5 min blocks of NetCDF data to any external ftp server.
For RS 485 communication a terminal software is required. For operating sys-
tems running Microsoft Windows™ the terminal software “DataClient” is sup-
plied together with the equipment.
NOTE
The RS 485 half-dublex interface does not allow sending and receiving
data at the same time. Accordingly, the interface has its own automatic
switching mechanism. This explains why users cannot send any com-
mands (refer to chapter 8.1) when receiving a data telegram. Data tele-
grams are described in chapter 8.3.3 to 8.3.5. Incoming initial <STX> and
end <EOT> character codes are indication of a running transmission ses-
sion.
8.1 List of configurable instrument parameters
Table 4 contains the most important setting options. They will be explained in
the following sections. For safety reasons and because they have a considerable
influence on the way the CHM 15k functions, some options are only available if
the ceilometer is set into a service mode (RS485, Ethernet).
Table 5 provides a list of additional read only parameters. These parameters are
partly saved on the EEPROM mounted on the laser optical module (LOM). They
have an impact on data evaluation and basic system settings. The tables are con-
taining the permissible value range for each parameter together with the default
value that is set at the time of product shipment and an indicator if service mode
is required or not.