Campbell CS125, Instruction Manual

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CS125 Present Weather Sensor
30
19 Dirty window
compensation
0-1 0 = No compensation applied
1 = Compensation for dirt on lenses applied.
The CS125 will compensate for up to 10% signal
loss due to dirt per lens.
0
20 Use CRC 0-1 0 = Disable command line CRC checking
(2)
1 = Enable command line CRC checking
Note: this does not affect communications via
DevConfig or terminal emulator.
0
21 Sensor power down
voltage
7-30 PSU Input voltage level below which the CS125
will enter low power mode. This is usually used to
protect batteries.
7.0
22 Relative humidity
threshold
1-99 Threshold at which the CS125 will define
obscuration as liquid or dry if a CS215 is fitted.
80%
(1) Hood heater override needs to be set to `1’ (off) when either no hood heaters are installed or
the hood heaters have no power connected to them. This will save power as the relay is not
enabled at low temperatures in this mode.
(2) If disabled the sensor does not check the validity of received data against the checksum sent.
It is, however, recommended that checksum checking is enabled to remove any chance of the
CS125 being configured incorrectly by accident.
14. Command line mode
The command line interface is broken down into three major commands. These
are GET, SET and POLL. The GET command is used to request all current user
settable values from the CS125. The SET commands sets user settable values and
the POLL command is used to request the current visibility and/or alarm
conditions from the sensor.
The CS125 can be configured to expect any commands sent to it to include a valid
checksum. For simple commands, e.g. GET and POLL, fixed value checksums
can be used (see the example programs). For more complex SET commands the
checksum needs to be calculated (see Appendix B). The use of the checksum is
disabled by default. It is recommended that the checksum functionality is enabled
where possible, especially when long cable runs are used, or in electronically
noisy environments.
14.1 The SET command
The set command is used to configure the CS125 via the command line. The SET
command is a single space delimited string that can be sent from any data logger
or PC equipped with an RS232 or RS485 port. The SET command and the
‘Device Configuration Utility’ software access identical settings within the
CS125, please refer to the ‘Device Configuration Utility’ section of this document
for a more detailed breakdown of the setting available here. This command is used
to change the default power up state of the sensor. See Section 14.2 if a setting is
going to be changed on a regular basis e.g. heater controls.
See Section 12 for more information on the values used by the `SET’ command.