Siemens ST PCS 7 manual 11/2, Integration of I/O modules in the hazardous area

© Siemens AG 2007

Process I/O

Introduction

■Overview
	The SIMATIC PCS 7 process control system offers various pos-	Signal groups of the SIMATIC S7-400 can be operated centrally
	sibilities for connecting I/O devices and for detecting and emit-	in the automation system and are mainly used in small applica-
	ting process signals through sensors and actuators:	tions or systems of limited distributed expansion.
	• Analog and digital I/O modules of the SIMATIC S7-400 oper-	Distributed process I/Os are mainly used nowadays: ET 200
	ated centrally in the automation system	remote I/Os in conjunction with classical field/process devices
	• ET 200M, ET 200S, ET 200iSP and ET 200pro remote I/O sta-	and HART field devices or intelligent field/process devices di-
	tions with an extensive range of cost-effective signal and func-	rectly on PROFIBUS. Decisive for this are properties such as:
	tion modules, connected through PROFIBUS DP to the auto-	• Modularity and consistency
	mation system (AS)	• Flexible adaptability to the plant structure
	• Direct AS connection of intelligent, distributed field/process
		• Minimum cabling and engineering requirements
	devices and operator terminals through PROFIBUS DP/PA (re-
		• Low commissioning, servicing and lifecycle costs
	dundant or in hazardous zones 0, 1, 2 or 20, 21, 22 also pos-
	sible)	• Wide technical bandwidth
■Design
	Integration of I/O modules in the hazardous area

Process control system

Industrial Ethernet

11

GAS	FM/UL	Class I Zone 2	Class I Zone 1	Class I Zone 0
	ATEX	Zone 2	Zone 1	Zone 0

	DUST	FM/UL	Class II Zone 2	Class II Zone 1	Class II Zone 0
		ATEX	Zone 22	Zone 21	Zone 20
2)	ET 200S	1)	Hazardous area

S7-400	2			Actuators/	1 0
			Ex e, Ex d	sensors
		ET 200M	1)			Actuators/
			Ex i, Ex e, Ex d
						sensors
			1)		ET 200iSP	1) 3)
			PROFIBUS DP
		Fieldbus
		Isolating Transformer				Ex i	Actuators/
							sensors
DP/PA link	1)		PROFIBUS PA
							Actuators/
							sensors
			SITRANS F		SITRANS P

ET 200 in explosive gas and dust atmospheres

1)Dust atmospheres: installation of components always in an enclosure with IP6x degree of protection.

2)With 10 A DC standard power supply

3)Also complies with FM/UL according to Class I Division 2

The diagram shows the various interfacing possibilities for the distributed I/Os of SIMATIC PCS 7 with consideration of various ambient conditions.

11/2

Siemens ST PCS 7 · November 2007