Wiring information for non-Hach flow meters
Refer to
Table 3
for the wiring information necessary to connect a non-Hach flow meter to the
junction box.
Terminal Signal
2
+12 VDC
power
output
3
Common
4
Pulse input
or Analog
input
5
Inhibit
2
All mains powered equipment that connects to the controller terminals must be NRTL listed.
3
Long-term operation in this state voids the warranty.
4
Source impedance of the driving signal must be less than 5 kΩ.
10 English
Table 3 Descriptions of the junction box terminals
Description
Power supply positive output. Only
use with Terminal 1.
Negative return of power supply.
When the power supply is used,
Terminal 1 is connected to earth
2
ground
.
This input is a sample collection
trigger from the flow meter (pulse
or 4–20 mA) or a simple floating
(dry) contact closure.
Liquid level input—Start or
continue the sampling program. A
simple float level switch can supply
input.
Auxiliary control input—Start a
sampler after the sampling
program on another sampler ends.
As an alternative, start a sampler
when a trigger condition occurs.
For example, when a high or low
pH condition occurs, the sampling
program starts.
Rating
Battery power to the IO9000 module: 12 VDC
nominal; Power supply to the IO9000 module:
15 at 1.0 A maximum.
Pulse input—Reacts to a positive pulse with
respect to Terminal 1. Termination (pulled low):
Terminal 1 through a series 1 kΩ resistor and
10 kΩ resistor. A 7.5 zener diode is in parallel with
the 10 kΩ resistor as a protection device.
Analog input—Reacts to the analog signal that
enters Terminal 2 and returns on Terminal 1. Input
burden: 100 Ω plus 0.4 V; Input current (internal
limit): 40 to 50 mA maximum
Absolute maximum input: 0 to 15 VDC with
respect to Terminal 1.
Signal to make the input active: 5 to 15 V positive-
4
going pulse
with respect to Terminal 1,
50 millisecond minimum.
Termination (pulled high): internal +5 V supply
through an 11 kΩ resistance with a series 1 kΩ
resistor and 7.5 V zener diode terminated to
Terminal 1 for protection. Trigger: High to low
voltage with a low pulse of 50 milliseconds
minimum.
Absolute maximum input: 0 to 15 VDC with
respect to Terminal 1. Signal to make the input
active: external logic signal with 5 to 15 VDC
power source. The drive signal must be typically
high. The external driver must be able to sink
0.5 mA at 1 VDC maximum at the logic low level.
A logic high signal from a driver with a power
source of more than 7.5 V will source current into
this input at the rate of: I = (V – 7.5)/1000 where I
is the source current and V is the power supply
voltage of the driving logic.
Dry contact (switch) closure: 50 millisecond
minimum between Terminal 3 and Terminal 1.
Contact resistance: 2 kΩ maximum. Contact
current: 0.5 mA DC maximum
3