Appendix - Siemens SIMATIC S7-300 Hardware And Installation Manual

Appendix

11
11.1 Installation
11.1.1 General rules and regulations for S7-300 operation
Introduction
In view of the many and versatile S7-300 applications, this chapter can only
describe the basic rules on its electrical configuration. You must observe at least
these basic rules if you want your S7-300 to operate free of trouble.
EMERGENCY-OFF devices
EMERGENCY-OFF devices to IEC 204 (corresponds to VDE 113) must remain
effective in all operating modes of the plant or system.
Startup of the system after specific events
The following table shows you what you have to observe when starting up a plant
again following specific events.
Table 11-1
Restart following a voltage dip or power
failure,
Startup after releasing the EMERGENCY
OFF device:
S7-300 Programmable Controller Hardware and Installation
A5E00105492-01
Startup of the system after specific events
If there is... What must not happen ...
No dangerous operating states may occur. If
necessary, force EMERGENCY-OFF.
An uncontrolled or undefined startup must
be avoided.
11
11-1