Emerson Process Management OXYMITTER 4000 Section HART/AMS, Overview, Connections

Hazardous Area Oxymitter 4000

Instruction Manual

IB-106-340C Rev. 4.1 July 2004

SECTION 7

HART/AMS

		The HART Communicator accomplishes its task
		using a frequency shift keying (FSK) technique.
	The HART option is not protected by
		With the use of FSK, high-frequency digital
	energy limiting barriers. It must not be	communication signals are superimposed on
	interfaced from within the hazardous	the Hazardous Area Oxymitter 4000’s 4-20 mA
	area. The 4-20 mA cables should be	current loop. The HART communicator does not
	routed and the connections made out-	disturb the 4-20 mA signal, since no net energy
	side the hazardous area. Note that this	is added to the loop.
	is the case even when using the in-
	trinsically safe version of the handheld	The HART Communicator may be interfaced
	communicator.	with a personal computer (PC), providing that
		special software has been installed. To connect
7-1 OVERVIEW		the HART Communicator to a PC, an interface
		adapter is required. Refer to the proper HART
	The HART Communicator is a handheld com-	Communicator documentation in regard to the
		PC interface option.
	munications interface device. It provides a
	common communications link to all microproc-	7-2 HART COMMUNICATOR SIGNAL LINE
	essor-based instruments that are HART com-
	patible. The handheld communicator contains	CONNECTIONS
	an 8 x 21 character liquid crystal display (LCD)	The HART Communicator can connect to the
	and 25 keys. A pocket-sized manual, included
	with the HART Communicator, details the spe-	Hazardous Area Oxymitter 4000’s analog output
	cific functions of all the keys.	signal line at any wiring termination in the 4-20
		mA current loop. There are two methods of
	To interface with the Hazardous Area Oxymitter	connecting the HART Communicator to the
		signal line. For applications in which the signal
	4000, the HART Communicator requires a ter-
		line has a load resistance of 250 ohms or more,
	mination point along the 4-20 mA current loop
		refer to method 1. For applications in which the
	and a minimum load resistance of 250 ohms
		signal line load resistance is less than 250
	between the communicator and the power
		ohms, refer to method 2.
	supply.		7

Rosemount Analytical Inc. A Division of Emerson Process Management HART/AMS 7-1