Siemens 7XV5653 Handbuch Seite 75

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Figure 3-3
Establishing a Modem Connection
In the case of test or laboratory systems, modems must not be connected to one another directly using tele-
communication connections. This would cause the tie line to have very low resistance. As a result of this,
transmission errors may occur because the receiver of the modem is overdriven.
Siemens recommends installing a 470-Ω resistor in each of the connections (see the following figure).
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Figure 3-4
Accessories, Binary signal transmitter 2-channel, Manual
C53000-G9050-C607-1, Edition 09.2019
Connecting-Cable Assignment
Connection Resistors
Application Examples
3.1 Transmission Modes
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