Thermo Scientific DensityPRO NAI Series, User Manual

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Operation
Communication Setup
Thermo Scientific DensityPRO User Manual 4-3
RS485
To communicate with multiple gauges via RS485 party line, each unit must be
assigned a unique unit identification number so it can be addressed individually. By
default, all gauges are assigned unit number one (1).
Note: Connecting a PC serial port (COM) to the RS485 port on the gauge
requires an RS485/RS232 converter.
To assign a unique unit number to each gauge, you must be able to communicate with
each one individually. Disconnect each gauge from the party line in turn and
communicate with the disconnected gauge directly. Alternatively, remove power from
all gauges except one and assign a unit number to the powered gauge. Repeat this
procedure for the remaining gauges.
If trouble arises when using another device on the RS485 chain, verify that the device
is properly terminated for its position on the chain. To terminate a device, connect a
120-ohm resistor between its RS485 +/- data terminals. Never terminate more than the
first and last device in the chain.
Ethernet
Each DensityPRO unit includes a 10 Base-T minimum Ethernet port on the Main
CPU PCA. Operators should ensure the area is non-hazardous before connecting or
disconnecting the Ethernet cable.
The Communication Setup screens also allow for configuration of the Ethernet port.
Figure 4-2. Communication Setup, Ethernet
13. Enable or Disable the Ethernet port.
14. Configure the Ethernet IP address, Subnet Mask, and Ethernet IP Gateway.
15. For Modbus using TCP/IP, enter the Modbus encapsulated port number and IP
port number in the indicated textboxes.