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APPENDIX F. NETWORKING
F.1 Description
The Model LC-2 Datalogger is capable of being networked by way of a single, optically isolated
RS-485 communications cable. Utilizing one 8001-5 (RS-232) or 8002-5(USB) RS-485 interface
adapter at the computer (data collection) end, up to 256 Model LC-2 Dataloggers* may be
networked. Also, the maximum network length* can be up to 4000 feet (1.22 km). RS-485 is
chosen as the transmission medium due to its inherent noise immunity and its capability to
support a bus type of network architecture. The 8001-5 and 8002-5 RS-485 interface adapters are
battery powered to allow for collection of data in the field. An AC adapter is also provided if
mains power is available.
Each datalogger appears as a “node” on the RS-485 bus, with its own unique address. In order to
communicate with a specific datalogger, the user transmits the address of the datalogger via the
#nnn command, where nnn represents the network address of the datalogger. Valid addresses are
1 thru 256.
Connect one end of the supplied RS-485 network cable into the 10-pin “Network In” connector
on the LC-2 enclosure, and connect the other end to the 10-pin “Network Out” connector on the
8001-5 or 8002-5 RS-485 interface. Connect additional LC-2 dataloggers in daisy chain fashion,
using RS-485 network cables to connect the “Network Out” of the first LC-2 to “Network In” of
the second LC-2, “Network Out” of the second LC-2 to “Network In” of the third LC-2 and so
on.
On the last networked LC-2 (the one physically furthest from the 8001-5 or 8002-5 RS-485
interface), set the TERMINATION JUMPER across pins one and two of PCB connector
JP1
. On all the remaining networked LC-2 dataloggers, ensure that this jumper is set across pins
two and three.
In order to access this jumper, the battery pack will need to be removed. For this reason,
LC-2 networks are typically configured at the factory before shipment.
Finally, it is helpful to set the datalogger ID# (see Section 4.9) to agree with the network address.
This will tend to eliminate any confusion when collecting data.
For further information, refer to Section 4.9 as well as Sections 4.20 through 4.24.
* The total number of networked dataloggers is limited by the total network cable length.
Contact a Geokon Sales Engineer for further information.