Hach AS950 - Page 18

Table 1 Half cable wiring information (continued)
Pin Signal Color
1
Description Rating
4 Liquid level
input or
Auxiliary
control
input
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.
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
5 Special
output
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.
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.
1
The wire color refers to the colors of multi-purpose cables (8528500 and 8528501).
18 English