Evoqua Wallace & Tiernan Depolox 3 plus, Manual

Page: 93 / 157

WT.050.560.001.UA.IM.0714 79
Depolox
®
3 plus ReSIDUAl ANAlYZeR
eVoQUA W3T140188
3.7.2.2 Interface Connection
The bus cable for the communication with the Depolox® 3 plus should be con-
nected to the following terminals:
Bus line A: Terminal 28
Bus line B: Terminal 27
NOTE: The RS485 interface of the Depolox® 3 plus is not galvanically isolated.
Each Depolox® 3 plus occupies two bus addresses of its own (e.g., 0 for chlo-
rine, 1 for pH or for fluoride). This means that in a bus system with Depolox®
3
plus -modules, each of the modules behaves as two separate bus users.
Figure 3.7 - Interface Connection
Both ends of the bus cable must be connected to a moving load Rt (150 Ohm).
Symmetry is assured at only one point of the bus. With a voltage supply of 5
V, the resistors Rd and Ru (390 Ohm each) connect to ground and 5 V. These
resistor values fit for transmission of up to 19200 Bit/s and a maximum bus
length of 1200 m. Symmetry and bus ends should be executed in the same
way at potentially isolated and non-isolated bus systems.