Hach 900 MAX manual 6.5.1, Analog Inputs Connection, Section, Deadband Concept

Section 6

Figure 28 Deadband Concept

pH

7.60

7.40

7.20

		Alarm Off
7.00		Deadband
6.80
6.60	Alarm On	Low Alarm Setpoint= 6.9 pH

6.40

6.5	Analog Inputs
6.5.1	Analog Inputs Connection
Note: 4–20 mA inputs must be		Analog voltage as well as analog current input signals are accommodated in a
isolated. Maximum load per unit is		single connector.
200 ohms.
		To connect the analog voltage signal (-4.0 to +4.0 V dc):
		1. Tie ground wire to Pin B (ground).
		2. Tie analog voltage wire to the appropriate voltage input pin
		(Pin C, E, or G).
		For example, to connect an analog voltage input to analog input channel 1, tie
		the ground wire to pin B and your positive wire to pin C.
		To connect an analog current signal (4–20 mA dc)
		1. Tie ground wire to Pin B (ground).
		2. Connect analog current wire to both voltage and current input pins for the
		appropriate channel (Pin C and D, or E and F, or G and H).
		Table 19Analog Input Pin Assignments
	Pin	Signal Description	Wire Color
	A	+12 V dc	White
	B	Signal Ground	Blue
	C	Voltage Input 1 (-4.0 V dc to +4.0 V dc)	Yellow
	D	Current Input 1 (4–20 mA dc)	Black
	E	Voltage Input 2 (-4.0 V dc to +4.0 V dc)	Red
	F	Current Input 2 (4–20 mA dc)	Green
	G	Voltage Input 3 (-4.0 V dc to +4.0 V dc)	Gray
	H	Current Input 3 (4–20 mA dc)	Brown
	J	not used	Violet
	K	not use	Orange
			Page 93
8990cm.fm			Analog Inputs