Siemens S5-135U/155U appendix Interference-Free Connection of Monitors

Installation Guidelines

3.6Interference-Free Connection of Monitors

These sections cover the following topics:

SFloating connection of cables at video inputs

SShielding and grounding concept

Information on selecting the components can be found in Catalog ST80.

3.6.1Interference-Free Connection of a Monitor to the CP of the S5 Controller

	Operator control and process monitoring systems from the COROS product
	family can be used with monitor connections. The physical arrangement of
	apparatus and the interference level of the environment are important for the
	interference-free connection of monitors to SIMATIC S5 control systems.
	The choice of monitor and video cables is governed by the following:
	S Whether the monitor and PLC are to be operated under low-interference
	conditions or
	S under industrial conditions.
Operation of the	Where the monitor and PLC are installed under low-interference
Monitor and PLC	environmental conditions and operated over short distances, the monitor and
under	PLC are at almost the same ground potentials. Interference and ground loop
Low-Interference	disturbances are therefore not expected.
Conditions
	In these cases, you can drive the monitor both via TTL signals and via analog
	signals. Digital cables or single-shielded coaxial cables can be used to
	transmit the video signals. Note that the braided shield of the coaxial cable
	serves as the return conductor and must not be connected to the shield bar.
	The monitor and communication processor (CP) are interconnected without
	additional shielding and grounding.
Operation of the	Where the monitor and PLC are installed under harsh industrial conditions
Monitor and PLC	and operated over great distances, the devices may be at different ground
under Industrial	potentials. These different ground potentials may cause interference and
Conditions	ground loop disturbances.

3-30	System Manual
	C79000-G8576-C199-06