Chapter 2 Installation and Configuration
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National Instruments Corporation 2-5 FieldPoint FP-1 000/FP-1001 U ser Manual
Figure 2-6. Host Computer Connected to Three FP-1001 Network Modules
The multidrop topology used in the networking configurations provides
protection against power failures at individual FieldPoint banks. It
eliminates the possibility that a power failure at one FP-1001 bank
might affect the communication between other banks in your network.
Because the FP-1000 provides an RS-485 repeater, a power failure at
that bank will affect communications.
Connecting to the Serial Ports
The following sections give information about the RS-232 and RS-485
ports on the network modules, and how to connect to them.
The RS-232 port on the FP-1000 network module is a full-duplex
interface. The RS-485 port on the FP-1000 and FP-1001 network
modules are optically isolated, full-duplex interfaces.
Caution: The RS-485 interface on both the FP-1000 and the FP-1001 modules is
isolated from the rest of the FieldPoint system, including the power supply,
backplane, and the RS-232 interface on the FP-1000. It is isolated with a
galvanic and optical isolation barrier, which has been designed and tested
to withstand fault voltages of up to 2500 Vrms. However, the safety rating
of this barrier is only for working voltages of up to 250 Vrms. Do not use
the isolation barrier of the RS-485 interface as a way to protect human
contact from common mode voltages of more than 250 Vrms. Also note that
while the RS-232 interface on the FP-1000 is isolated from the RS-485
interface, it is NOT isolated from the power supply inputs (the V and C
terminals).
Host Computer with
RS-485 Board Installed
FP-1001FP-1001FP-1001
RS-485

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