Hach AS950 Basic Installation And Maintenance page 16

Figure 10 Controller connections
1 Sensor 2 port (optional)
2 Thermal unit port (AWRS only)
3 Power supply port
4 Sensor 1 port (optional)
Connect a Sigma 950 or FL900
If sample pacing is flow based, supply the controller with a flow input signal (pulse or 4–20 mA).
Connect a Sigma 950 or an FL900 Flow Logger to the AUX I/O port.
As an alternative, connect a flow sensor to a sensor port. Refer to
Item to collect: Multi-purpose auxiliary full cable, 7 pin
1. Connect one end of the cable to the flow meter. Refer to the flow meter documentation.
2. Connect the other end of the cable to the AUX I/O port on the controller.
Connect a non-Hach flow meter
To connect a non-Hach flow meter to the AUX I/O port, do the steps that follow.
Items to collect: Multi-purpose auxiliary half cable, 7 pin
1. Connect one end of the cable to the AUX I/O port on the controller.
2. Connect the other end of the cable to the flow meter. Refer to
Note: In some installations, it is necessary to connect external equipment to the Pulse input, Special output
and/or Program Complete output with long cables. Since these are ground-referenced pulse interfaces, false
signaling can be caused by transient ground differences between each end of the cable. High ground
differentials are typical in heavy industrial environments. In such environments, it may be necessary to use
third-party galvanic isolators (e.g., optocouplers) in line with the affected signal(s). For the Analog input,
external ground isolation is typically not necessary because the 4–20 mA transmitter typically supplies isolation.
Figure 11 Auxiliary connector
16 English
5 USB connector
6 Rain gauge/RS485 port (optional)
7 Auxilliary I/O port
8 Distributor arm/Full bottle shut-off port
Connect a sensor
Figure 11
on page 18.
and Table 1.