Teledyne 4220 installation and operation guide Optional Outputs, Interrogator connector

4220 Flow Meter

Section 2 Programming

The following will appear if you are measuring D. O:

DO ENABLE/ALARM

HYSTERESIS X.XXX PPM

	(or mg/l depending on units selected in Program.)
	A set of menus similar to those shown above for pH, D.O., and
	temperature will then appear for the YSI 600 Sonde, if you have
	selected it. You can set hysteresis for YSI-pH, YSI-D.O., YSI-Con-
	ductivity, and YSI-temperature, if these parameters have been
	turned on in previous program selections.
2.4.2 Optional Outputs	After all the HYSTERESIS menus have been set, press Enter.
	The display will return to the Setup menu. This time select
	OPTIONAL OUTPUTS with the arrow key. Press Enter.
	OPTIONAL OUTPUTS
	• ANALOG OUTPUT • • SERIAL OUTPUT • • ALARM BOX •
	ALARM BOX – refers to an external accessory used to signal
	alarms from flow meter measurements. See Section 5 for more
	information about the Alarm Box. Note that choice of SERIAL
	OUTPUT will eliminate ALARM BOX as an option. Likewise,
	choice of ALARM BOX will eliminate SERIAL OUTPUT as an
	option.
	If you select any of these OPTIONAL OUTPUTS, the flow meter
	will request that you turn them on or off. If you are running on
	battery, select OFF for all unused outputs.
	ANALOG OUTPUT – refers to the flow meter’s capability of
	managing associated equipment through a 4-20 mA current loop.
	The 4-20 mA current loop is a common method used to control
	industrial processes that are variable (rather than just fully off
	or on). At the lower value (4 mA) the control is turned off (0%); at
	20 mA the control is completely turned on (100%). In between,
	rates range from 1 to 99%. A typical application is a chlorinator,
	which must vary in application of the chlorine gas as the amount
	of water passing through the system increases or decreases.
	Current ranges other than 4-20 mA are also in use, although
	they are less common than 4-20 mA. Examples are 0-20 mA (sup-
	ported by the flow meter on the internal card only) and for longer
	current loops, 10-50 mA (not supported by the flow meter).
	Teledyne Isco offers two different arrangements for the 4-20 mA
	control circuit. You can have either or both with the same flow
	meter. One arrangement requires the use of an external
	accessory, the 4-20 mA Output Interface (see Section 5). This
	module connects to the flow meter and a source of AC power and
	contains the circuitry necessary to create the 4-20 mA current
	loop. This accessory connects to the flow meter through the
	Interrogator connector.
	The other 4-20 mA option is a board installed inside the flow
	meter that contains circuitry for up to three separate, isolated
	4-20 mA current loops. This option can also be ordered with one

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