Hach-Lange SIGMA SD900 Refrigerated Sampler and All Weather Refrigerated Sampler User Manual - Manual (Page 102)

100
Wiring for non-Sigma flow meters
C
Pulse/
Current
input
Orange
This input triggers sample collection.
The signal may be generated by:
• An external flow meter or other
device with an appropriate pulse or
4-20mA control output.
• Simple floating (dry) contact
closure.
• An external flow meter or other
device with a 4-20mA current
output.
(For more information on flow pacing,
see the instruction sheet supplied with
the 4—20 mA input.)
In pulse mode, this input responds to a positive pulse
with respect to Common (pin B). It is terminated
(pulled low) to Common (pin B) through a series
1 k
Ω resistor and 7.5 V zener diode.
In current mode, this input responds to current
entering pin C and returning on pin B (common). The
input burden is 100 ohms plus 0.4V. The maximum
input current is internally limited at 40-50 mA but long
term operation in this state constitutes abuse and is
not warranted.
Absolute maximum input: 0 to 15 VDC with respect
to Common (pin B). Signal required to activate input:
5–15 V positive going pulse with respect to common
(pin B) of at least 50 millisecond duration. Source
impedance of driving signal should be less than
5 k
Ω.
Dry contact (switch) closure of at least 50 millisecond
duration between pin A (12 VDC) and pin C (Pulse
Input). Contact resistance should be less than 5 k
Ω.
Contact current will be less than 8 mA DC.
D
Liquid level
actuator/aux
iliary control
input
Black
This input sends a signal to the
microprocessor inside the sampler
causing it to "wake up" and begin or
resume its sampling program.
Applications for this input include:
A simple float level switch (dry contacts)
may be used to actuate the sampler
when liquid is present.
Start this sampler after another sampler
has finished its program.
Start the sampler in response to some
user-defined condition from an external
device that provides an appropriate
control signal. For example a pH meter
could be used to initiate sampling in
response to a high or low pH condition.
This input is terminated (pulled high) to an internal
+5 V supply through an 11 k
Ω resistance and
protected by a series 1 k Ω resistor and 7.5 V zener
diode terminated to Common (pin B). The input
responds to a high to low voltage transition with a
logic low pulse width of at least 50 milliseconds.
Absolute maximum input:
0 to 15 VDC with respect to Common (pin B). Signal
required to activate input:
External logic signal having 5-15 VDC power source.
The drive signal should be normally high. The
external driver should be capable of sinking 0.5 mA
@ 1 VDC maximum at the logic low level.
A logic high signal from a driver with power source of
greater 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
V is the power supply voltage of the driving logic.
Dry contact (switch) closure of at least 50 millisecond
duration between pin D and pin B (common).
Contact resistance should be less than 2 k
Ω. Contact
current will be less than 0.5 mA DC.
E
Special
output
Red
Normally at 0 VDC, this line goes to +12
VDC upon any of the selected events
described in
section 5.3.2 on page 66 .
This output is thermally protected against short
circuit currents to common (pin B). Limit external
load current to 0.2 A.
The output is normally logic low (0 VDC) with respect
to common (pin B). Active high output levels are:
15 VDC nominal when using AC power to power the
sampler
12 VDC nominal when using battery 8754400 to
power the sampler.
Table 9 Half-cable wiring information for non-Sigma flow meters (continued)
Pin
Signal
description Wire
color
1
Purpose Rating