The horizontal lines are just repeated static values with a muted color.
The vertical lines are managed by clock and for one single trigger, they are set to a high value (IE: 15v for midnight), but the rest of the time the value is anything below the lowest value on the scale, or even just zero.
Below is the graph feed that always occurs (3 outputs, 1 & 3 feed other nodes, 2 is the graph). Just need to manage the values as you require. I do control the output to the graph via clock (not upon msg.payload). The latest msg.payload graph value(s) (voltage, amps) are held in context (but they are updated each second). I found setting colors is a tad tricky (which feed is what color).
For example, if the ac_charge line (blue) should show, it is set to 10.5v while the slr_charge line (yellow) is then set to below 10v. This gives an illusion of the line color changing.
return [ null, [voltage, highline, baseline, badline, midnite, ac_charge, slr_charge, sun_line, amps], voltage ];
