An in depth look at how how the Smart Bilge current loop output works.
The SmartBilge has the benefit of a current loop output for reading the displayed PPM Value remotely. This can be used in conjunction with a 3rd party display or the vessels DCS system.
This output effectively mimics and directly correlates to the SmartBilge monitors displayed PPM value. The mA Signal can be changed between 0-20mA and 4-20mA In the customer menu.
When set to 4-20mA, a current of 4.0mA Will be emitted from the output terminals of the controller PCB, when 0ppm is displayed. When 30ppm is displayed, the mA Output will increase to 20.0mA. The scale is linear in between so a displayed value of 15ppm will emit 12.0mA.
When set to 0-20mA, a current of 0.0mA Will be emitted from the output terminals of the controller PCB, when 0ppm is displayed. When 30ppm is displayed, the mA Output will increase to 20.0mA. The scale is linear in between so a displayed value of 15ppm will emit 15.0mA.
The mA Output terminals of the Smart bilge can be located in the centre of the controller PCB (Behind the LCD Display. See https://hub.rivertrace.com/knowledge/controller-pcb-removal-and-replacement for reference). This is a green, 2 pin terminal marked as J8 - Circled below;
When checking this output with a MultiMeter, ensure that your meter is capable of measuring mA DC and configured correctly.
If the mA Output is inaccurate, the controller PCB Must be replaced as this is not serviceable onboard. The Controller PCB Can be replaced by crew but be aware that the IMO Log data is also stored on this PCB So an IMO Dump should be made prior to removing the faulty PCB.
The Tolerance of the mA Output is +/- 0.1mA. Please also consider the accuracy of your MultiMeter when measuring.