Panametrics Aurora H2O, User Manual

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Chapter 2. Installation
16 Aurora H2O User’s Manual
2.8 Making Electrical Connections (cont.)
Multi-drop RS-485:
For multiple Aurora H2O units connected in daisy-chain fashion to the RS485 interface, it is important that the
farthest unit away from the transmitting device be the only unit incorporating any termination (see Figure 27 below).
All other units must have jumpers J15 and J16 in positions 2 & 3 (default setting from the factory). For more details on
RS-485 wiring or operation, refer to TIA/EIA-485-A Specification.
Figure 27: RS-485 Mode Termination - Install Jumpers at J15 and J16, Pins 1 and 2
Note: The internal terminations MUST be in the default (unterminated) position for operation in RS-232 mode.
• For operation on RS-232, connect RS-232(TXD) to (+), RS-232(RXD) to (–), and RS-232(GND) to RTN (see
Figure 28 below).
Figure 28: Input/Output Connections
J16
1
2
3
J15
1
2
3