Tachometer Output Most GenBoard outputs is only pulling the output low (0 volts)
If your tachometer wants 12V or 5V signals, wire up a external pullup resistor use Tachometer Divider if you want a lower frequency to your tachometer

Config switch settings
confswitch=00 disabled
confswitch=C3=195 does load_variables(1) if mcp3208 ch3 goes low
confswitch=D3=211 does load_variables(0) if mcp3208 ch3 goes high
confswitch=83=131 does load_variables(1) if mcp3208 ch3 goes low AND misc1 condition is true
confswitch=93=147 does load_variables(0) if mcp3208 ch3 goes high AND misc1 condition is false
any mcp3208 analog input channel can be chosen with confswitch bit 0:3 (ch 0..7)