Hach AS950 Instalación Y Mantenimiento Básicos página 18

Pin Signal Color
3 Pulse input Orange This signal is a sample
or Analog
input
4 Liquid level Black
input or
Auxiliary
control
input
6
Long-term operation in this state voids the warranty.
7
Source impedance of the driving signal must be less than 5 kΩ.
4
The wire color refers to the colors of multi-purpose cables (8528500 and 8528501).
18 English
Table 1 Half cable wiring information (continued)
4
Description
collection trigger from the
flow logger (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
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): 40 to
6
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 positive-going pulse
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
7
with respect