User Guide

CONNECTIONS

The connections for the 2-pin RS485 terminal provided are

as follows:

The instrument has no internal line termination. To terminate

the line, an external resistor equal to the characteristic line

impedance (typically 120Ω) must be added at both ends of

the line.

The RS485 can connect up to 31 Digital Transmitters on the

same physical network. All the units are slave devices and

are monitored and controlled by a single master station (typi-

cally an industrial PLC or PC).

Each unit is identified by its RS485 address, included in the

00 to 99 interval, which corresponds to the Instrument ID

configured through the setup item G.11.

(If the instrument does not recognize the address within the

command string, then it discards all the following bytes).

To avoid erroneous readings in Open-Line

conditions, pull-up and pull-down resis-

tors should be connected as shown (Fail

Safe Open Line protection method).

The Fail-Safe resistors are connected only to one unit in the

line, and their value depends on the application and char-

acteristic impedance of the connection cable.