Campbell CS135, User Manual

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User Guide
15
4.5.2.2 Communications connections
The communications cable is terminated at one end with a removable 9 pin
D-connector (DB9). The D-connector can be connected directly to a PC or data
logger such as the Campbell Scientific CR1000 using a suitable interconnecting
cable such as the SC110. Connections and wire colours are shown in Fig 4.4. The
connector can easily be removed for direct connection to screws terminals.
If hardware handshaking is not to be used then pins 7 and 8 should be connected
together.
The type of cable supplied is not recommended for lengths
greater than 10 m. In particular, longer length RS485 cables
should incorporate twisted pairs. Please contact Campbell
Scientific if you wish to use a longer length of cable.
Fig 4.4 Cable Connections
Tilting the unit, see Fig 4.2 will make wiring easier.
4.5.3 USB Connection
A USB port is provided inside the enclosure to aid on-site maintenance. This
allows communication of commands to the CS135 and responses in the same form
as the main serial port except that the baud rate is fixed at 115200 (see Fig 4.5).
4.5.4 SDI-12 Connection
A SDI-12 port is provided to allow interface to other sensors but will only be
active in future operating systems.
CAUTION