Functional Procedures; Using Serial Interfaces; Interface Converter - Gantner Q Series Manual

6
6.1
6.1.1
Q.series
Gantner Instruments Test & Measurement GmbH
Functional Procedures → Using serial interfaces
6

Functional Procedures

This chapter explains various important settings and processes
more comprehensively than in the previous chapters, for exam-
ple, to provide you with decision-making aids for the interface
parameters or the settings of the modules.

Using serial interfaces

The interface on the Q.bloxx modules is based on the RS-485
standard. This means that data transmissions over distances up
to 1 km and the connection of several devices to one interface is
possible; the RS-485 interface is therefore a bus-type interface.
With the Q.series up to 16 devices (modules) can be connected
per bus segment.
PCs are however usually "only" equipped with one RS-232 inter-
face with which, according to the standard, a maximum line
length of 20 m is admissible and only one device can be connected
per interface. Therefore for communication with the Q.bloxx
modules you need either an RS-485 interface card in the PC or an

interface converter.

One technique is particularly important to facilitate large line
lengths: the so-called bus termination. This comprises resis-
tances which must be connected to the end of the lines, so that
the signal is dampened by these line terminations and no reflec-
tions occur at the end of the line which would attenuate the sig-
nal.
You will find further information on these topics and on connec-
tion techniques in this section.
Interface converter
Gantner Instruments Test & Measurement GmbH offers you two
different interface converters:
1. The compact interface converter ISK 200 (bench-top unit)
The converter has an integrated DC power supply for the con-
nected modules and automatic baud rate detection. The
power supply via the 230 V mains, the bus connection and the
output voltage of 24 V
another.
2. The interface converter ISK 101
The converter is integrated directly into an interface cable.
The terminating resistance is also located in the connecting
plug and is always active.
are electrically isolated from one
DC
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