2
O&M Manual
Rev-D (2/16)
Table of Contents
Part 1 ā Modbus Description ____________________________________________________________ 3
1.1 Modbus Technical Overview........................................................................................................ 3
1.2 Modbus Connection ..................................................................................................................... 5
1.3 Registers and Coils ...................................................................................................................... 5
1.4 RS-485 Communication ............................................................................................................... 6
1.5 Cable Specification ...................................................................................................................... 7
1.6 RS-485 Line Drivers/Receivers ................................................................................................... 8
1.7 120 Ohm Termination .................................................................................................................. 8
1.8 Bias .............................................................................................................................................. 8
1.9 Drops ........................................................................................................................................... 9
1.10 Daisy Chaining ............................................................................................................................. 9
1.11 Shielding .................................................................................................................................... 10
1.12 Slave Connection Detail ............................................................................................................ 10
1.13 Q46 Register Assignment .......................................................................................................... 12
Table of Figures
Figure 1 - Modbus Terminal Connections ..................................................................................................... 4
Figure 2 - Modbus Set-up Screen ............................................................................................................... 11
Figure 3 - Q46 Modbus Input Register Data ............................................................................................... 12
Figure 4 - Status Register Bitfield Flags ..................................................................................................... 13
Tables of Registers
Q46H/62, Q45H/63 or Q46H/79PR Residual Chlorine Tables _________________________________ 14
Q46H/64 Dissolved Ozone Tables ______________________________________________________ 15
Q46H/65 Dissolved Chlorine Dioxide Tables ______________________________________________ 16
Q46P & Q46R pH and ORP Tables _____________________________________________________ 17
Q46N Total and Free Ammonia Tables __________________________________________________ 18
Q46C4 or Q46CT Conductivity Tables ___________________________________________________ 19
Q46F Fluoride Tables ________________________________________________________________ 20
Q46T Turbidity Tables ________________________________________________________________ 21