Hach AS950 AWRS Manual De Instrucciones página 18

Pin Signal Color
4 Liquid level Black
input or
Auxiliary
control
input
5 Special Red
output
6 Program Green
Complete
output
7 Shield Silver
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
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.
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.
Typical state: open circuit. This
output goes to ground for
90 seconds at the end of the
sampling program.
Use this output to start another
sampler or to signal an operator
or data logger at the end of the
sampling program.
The shield is a connection to
earth ground when AC power is
supplied to a sampler to control
RF emissions and susceptibility
to RF emissions.
Rating
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.
This output is an open drain output with 18 V
zener clamp diode for over-voltage protection.
The output is active low with respect to pin 2.
Absolute maximum ratings for the output
transistor: sink current = 200 mA DC maximum;
external pull-up voltage = 18 VDC maximum
The shield is not a safety ground. Do not use
the shield as a current carrying conductor.
The shield wire of cables that are connected to
the AUX I/O port and are more than 3 m (10 ft)
should connected to pin 7.
Only connect the shield wire to earth ground at
one end of the cable to prevent ground loop
currents.