Hach IO9000 Instrucciones Para El Usuario página 14

Figure 7 Externally-powered loop
1 Analog output
2 External power supply
Connect the digital inputs
The I/O module has four digital inputs
Refer to Figure 4 on page 11,
Specifications on page 3 for the digital input specifications.
Each digital input has a positive terminal and a shared common with an input resistance of 120 kΩ.
The default threshold is 1.5 V. When the optional customer supplied threshold is used, the threshold
is set at 50% of the voltage applied to the threshold pin (0 to 25 VDC).
Pin
COM (pin 1)
THRESHOLD
COM
IN #
Connect the digital outputs
Do not use the digital outputs for process control functions such as pump on/off switching or water system
shutdown. The digital output connections do not replace a PLC (programmable logic controller).
The I/O module has four digital outputs. Connect a compatible device such as a remote alarm
indicator, buzzer or PLC to the digital outputs. Refer to
Table 4 to connect the digital outputs. Refer to
specifications.
The digital outputs are independent floating switches when the PULLUP V input and associated
internal pull-up resistors are not used. The switches are normally open. The switches close when the
user-selected alarm conditions occur.
To use the optional PULLUP V input and the related internal 10 kΩ internal pull-up resistors, supply
the applicable voltage to the PULLUP V and COM (pin 14) pins. Then, connect a jumper from the
OUT # LO pin to the COM pin. The output signal logic is active low.
Pin
OUT # HI
OUT # LO
3
The digital inputs are not supported by the AS950 controller firmware at the initial release.
14 English
3
. Connect a remote device and/or a switch to the digital inputs.
Figure 5 on page 12 and
Table 3 Wiring—digital inputs
N O T I C E
Specifications
Table 4 Wiring—digital outputs
3 External device
Table 3 to connect the digital inputs. Refer to
Description
Negative for THRESHOLD
25 VDC maximum
Negative
Positive
Figure 4 on page 11,
on page 3 for the digital output
Description
Positive
Negative
Figure 5 on page 12 and