Section 3 Connecting To External Devices; Using The 12 V Dc Connection; Using The Auxiliary Connection - Hach Sigma 900 User Manual

Section 3

3.1 Using the 12 V dc Connection

3.2 Using the Auxiliary Connection

Pin Signal Description
A 12 V dc
B ground
C Pulse Input
8837ext.fm
Connecting to External Devices
The Sigma 900 All Weather Refrigerated Sampler can connect to several
different external devices. This chapter describes the characteristics of
each interface connector signal on the sampler and pin assignments.
Section 5 contains information on programming the sampler to connect to
external devices.
Pin
A
B
The 12 V dc connection supplies power to the sampler controller electronics.
Power is normally supplied to the sampler controller electronics from either a
battery or a power supply located in the pocket directly behind the sampler
controller housing.
In the event of a power outage, an optional 12 V dc battery backup
(Cat. No. 8801) is available. The battery backup maintains power to the
sampler when ac power fails.
F
E
D
Wire
Color
Powers an external device or flow meter. Power is supplied form another
White
source such as a battery. Must be used in conjunction with Pin B (ground).
Connected to dc ground and is isolated from the earth ground found in the
Blue
ac power line.
With the sampler in Flow Proportional mode and connected to an external
flow meter, a 5 to 17 V dc input pulse lasting at least 25 milliseconds will
cause the sampler to decrement one count. The 12 V dc line found on Pin
A can be used directly with a simple contact closure to Pin C or an external
Yellow
5 to 17 V dc pulse may be applied providing the ground side of the
external signal is connected to the sampler ground at Pin B. This count is
actuated at the beginning of the input signal (the leading edge of the
pulse).
Signal Description
Ground
12 to 17 V dc, unregulated
A
B
C
Description
Connecting to External Devices
Rating
13.8 V dc
nominal
13.8 V dc
nominal
5 to 17 V
dc pulse
with a
duration
of at least
25 ms.
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