18Installation3.5 InterfacesThe DR 3900 features three USB ports and one Ethernet port asstandard, located on the front and rear sides of the instrument(Figure 1 and Figure 2, page 17).The USB type A ports are used for communications with a printer,USB memory stick or keyboard. A USB memory stick can beused to update the instrument software.The USB type B port is used for communications with a PC. Theoptional Hach Data Trans software (refer to Section 9, page 137)must be installed on the PC for data transfer.A USB hub may be used to connect several accessories at atime.Note: USB cables must not be longer than 3 m.These USB ports permit data to be exported to a printer or PCand also allow the instrument software to be upgraded (refer tosection 6.8.2, page 111). The Ethernet port supports real-timedata transfer in local networks, LIMS systems or SC controllers.Only use a shielded cable (e.g. STP, FTP, S/FTP) with amaximum length of 20 m for the Ethernet port.3.6 Cell compartments, cell adapters and light shield3.6.1 Cell compartments and adaptersThe DR 3900 has two cell compartments (Figure 3). Only one celltype at a time can be used for a reading.Cell compartment (1) for:• 13 mm round cellsNote: Cell compartment (1) contains barcode detection forcells.Cell compartment (2) for:The following cell types can be used in cell compartment (2).• Without cell adapter A, 50-mm cells, 1-inch rectangular cellsand 1-inch flow cells can be used directly in cell compartment(2).• With cell adapter A: 10 mm rectangular cells, 1-inch roundcells and AccuVac® vials.Note: These cells must be inserted using cell adapter A.
