EDS470 - Bender

System c omponents
AGE470
By means of the coupling device AGE470, the range of nominal voltage of the
EDS470 system can be extended to AC 790 V resp. DC 960 V. About the
connection refer to examples of complete circuits.
AGE470
R
E
Serial interface RS485
The communication between several evaluators EDS470-12 and with the control
and indicating device PRC470 as well as the test device PGH471 is carried out by
means of a standardized serial interface RS485. The interface is a two-wire
connection (device terminals A and B).
The specification of the interface RS485 restricts the maximum cable length of the
bus to 1200 m. For longer cables, additional measures (installation of repeaters,
see chapter SYSTEM EXTENSIONS) are necessary. Cables longer than 1200 m
should only be conceived after consulting BENDER.
If interface cables are realized as subcircuits, the maximum cable length is
restricted to 1 m. Longer subcircuit cables must be tested taking into
consideration the conditions of the respective installation. The safe
communication cannot be guaranteed for longer subcircuit cables.
Terminating serial
interfaces
The serial connection must be terminated at both ends with a resistor of 120 Ω
(0.4 W) (see picture). For each PRC470 and each PGH471 are 2 resistors
included. Attention: single feeders are not terminated.
1. device ... device last device
A B A B A B
120Ω
single feeder max. 1 m
120Ω
maximum length of the RS485 bus: 1200 m
TGH 1243E/02.2000
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