5
4.1.
Quick 4-20mA Start
Note: The negative 24V power terminal (power ground) and the negative 4-20 mA terminal on the ST-
735 probe are internally connected.
If the power ground terminal and the negative 4-20 mA terminal in the controller are internally
connected (non-isolated 4-20mA input), it is unnecessary to connect the 4-20 mA negative wire (blue) to
the 4-20 mA negative terminal in the controller. If a separate DC power supplier other than that from
the controller is used, make sure that the output from the power supply is rated for 22-26 VDC @ 65mA.
Follow the wiring table below to connect the ST-735 probe to a controller.
Wire Color
Designation
Red
24 V
Black
Power ground
White
4-20 mA +
Green
4-20 mA - Internally connected to the power ground
Blue
RS-485 A
Yellow
RS-485 B
Clear Shield, solution ground