Rs 485 Digital Interface (Rs Option) - wtw EcoLine LF 170 Bedienungsanleitung

RS 485 digital interface (RS option)

The RS 485 interface operates with differential levels that are not susceptible to
interference. In this way, cable lengths of up to 1000 m long can be implemented. The
instruments are connected via a 2-wire line. A twisted 3-wire line is recommended for
greater lengths or a larger number of instruments; the third line is used as a reference
potential (GND), to compensate for any possible differences in potential that may
occur.
Terminate every bus with a resistor using the software (see Parameterizing).
The last device on the bus must provide the terminating resistor, i.e. in
parameterization menu item
connected additionally within the bus connection (
notr
disconnected (
If only one device is used, this is also effectively the last device and the terminating
resistor must be connected (
All other technical data as well as operating instructions are given in RS 485
Operating Manual .
USA and Canada:
Use the MCB 17x conduit box for the power supply and relay/alarm
contacts. Follow the installation instructions.
Installation
PIF
, the last device must have the termination
= no Termination) in all other devices.
tr
).
tr
T
= ermination) and
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