Lufft CHM 15k, Руководство пользователя

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Operating Manual CHM 15k R13 / 07-2019
Communication via RS485 & Ethernet 26
8
Communication via RS485 & Ethernet
The CHM 15k supports the interfaces RS485 (section 8.2) and Ethernet (section 8.7) for communication
with the device. Both offer the possibility of data transfer of the measured values and the configuration of
the device and can be used at the same time.
A web interface is part of the device for the communication via the Ethernet interface. Regardless of the
operating system, the ceilometer can be accessed through various web browsers.
The web interface can also be used to manually download the measured data stored in NetCDF daily
files on a built-in SD card (section
8.4 ). Also implemented on the system is an AFD (ftp) service (section
8.8 ) which, for example, allows data in the form of 5-minute blocks of NetCDF files to be transferred to
an external FTP server.
The RS485 communication requires a terminal program.
Transmit and receive with RS485
The RS485 interface does not allow simultaneous send and receive operation (half
duplex mode). Accordingly, the interface is automatically switched internally. Hence,
while receiving an automatically transmitted data telegram (see
0
Standard data telegram to 8.3.5 Raw data telegram ), it is not possible to send other
commands (as described in 8.1).
The incoming start and end flags <STX> and <EOT> indicate a current receive
transmission.
8.1 List of configurable parameters
Table 4 contains the most important settings. These are explained in the following sections. To prevent
unwanted effects on the functioning of the device, some options can only be set in service mode (RS485)
or in superuser or service user mode (Ethernet), such as the device name.
Table 5
shows a list of parameters with read-only properties. These parameters are stored in part on the
EEPROM on the measuring unit and affect data evaluation and the basic system settings.
The tables contain the permissible value range for each parameter and the default value on delivery of
the device. They also contain an indication when the service mode is required.
Parameter Short
cmd
RS485
Default
value Range / short description
AfdMode* AFD 0 0; 1, switch on the ftp data transfer
Altitude(m) ALT 0 0
– 9999, unit is always in meters!
ApdControlMode* ACM 3 0, 1, APD mode, only change if you know
what to do
Azimuth AZT 0 0-360 degrees (x 100)
Web
(e.g. 12.25
RS485
and 1225
Web
)
Baud BAU 3 2
– 7 (4,800 – 115,200 baud)
BaudAfterError* BAE 3 2
– 7 (4,800 – 115,200 baud)
BlowerMode BLM 0 0
– 4
ChmTest* CHT 0 0; 1
CloudDetectionMode CDM 0 0; 1
Comment COM Comment; also stored in the NetCDF file
Comment 1 RS485 CM1 Additional comment field (31 characters)
Comment 2
RS485
CM2 Additional comment field (31 characters)
Comment 3
RS485
CM3 Additional comment field (31 characters)