Hach AS950 AWRS Installationsanleitung Seite 12

differentials are typical in heavy industrial environments. In such environments, it may be necessary to use
third-party galvanic isolators (e.g., optocouplers) in line with the affected signal(s). For the Analog input,
external ground isolation is typically not necessary because the 4–20 mA transmitter typically supplies isolation.
Pin Signal
1 +12 VDC
power
output
2 Common
EN
3 Pulse input
or Analog
input
4 Liquid level
input or
Auxiliary
control
input
5 Special
output
4
The wire color refers to the colors of multi-purpose cables (8528500 and 8528501).
5
All mains powered equipment that connects to the controller terminals must be NRTL listed.
6
Long-term operation in this state voids the warranty.
7
Source impedance of the driving signal must be less than 5 kΩ.
12 English
Table 1 Half cable wiring information
4
Color Description
White Power supply positive output.
Only use with pin 2.
Blue Negative return of power supply.
When the power supply is used,
pin 2 is connected to earth
5
ground .
Orange This signal is a sample collection
trigger from the flow logger (pulse
or 4–20 mA) or a simple floating
(dry) contact closure.
Black 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.
Red This output goes from 0 to
+12 VDC with respect to pin 2
after each sample cycle. Refer to
the Mode setting of the hardware
settings for the AUX I/O port.
Refer to the AS950 operations
documentation.
Rating
Battery power to the I/O module: 12 VDC
nominal; Power supply to the I/O module: 15 at
1.0 A maximum.
Pulse input—Reacts to a positive pulse with
respect to pin 2. Termination (pulled low): pin 2
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 pin 3 and returns on pin 2. Input burden:
100 Ω plus 0.4 V; Input current (internal limit):
6
40 to 50 mA maximum
Absolute maximum input: 0 to 15 VDC with
respect to pin 2.
Signal to make the input active: 5 to 15 V
7
positive-going pulse with respect to pin 2,
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 pin
2 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 pin 2. 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 pin 4 and pin 2. Contact
resistance: 2 kΩ maximum. Contact current:
0.5 mA DC maximum
This output has protection against short circuit
currents to pin 2. External load current: 0.2 A
maximum
Active high output: 15 VDC nominal with AC
power to the AS950 controller or a 12 VDC
nominal with battery power to the
AS950 controller.