I’m attempting to monitor water consumption with my emonpi. My meter is an Elster v200 and I bought an Elster PR6 pulse counter
I know others started working on similar setups but I didn’t see any reports of success. E.g.
Relevant facts about the Elster PR6:
– the red CH2P wire is the secondary pulse output (compensated for backwards flow)
– the black GND wire is common/0v
– the PR6 expresses K-factor as x:y where y is the factor of the CH2P wire. In my case y=1 so 1 pulse will be 1L
– outputs are all “open drain”
– PR6 data sheet illustrates an output pulse as being a short ‘0’, with a ‘1’ when not pulsing (as a complete newbie this was a surprise to me, I expected a pulse to be a logic ‘1’)
– pulse width is 80ms
Pull-up resistor or not?
– the PR6 data sheet says the outputs may be connected via pull-up resistor to up to 30v. It makes sense intuitively to me to connect a pull-up resistor between Pulse and Power so that when not pulsing, the output is held high. There is a picture in an Elster guide showing a 2.2kohm resistor used for this purpose
– HOWEVER, there is a comment on the ever-helpful Wiki on the RJ45 connector (https://wiki.openenergymonitor.org/index.php/EmonPi#RJ45_Socket), that there is an input pull-up already inside the IRQ input
So I decided against a second pull-up resistor, and connected the red PR6 wire (CH2P) to Pin 6 of the emonpi’s RJ45 connector; and the black PR6 wire (common) to Pin 5 of the emonpi’s RJ45.
So far pulse count appears to be well in line with the metered usage, so I am optimistic, but am woefully underqualified so hope that an expert can correct any major bloopers and perhaps this will help anyone with the same setup