Get pressure from Pneumaticcraft

Hello,

I'm searching for a while now how to get the pressure from Pneumaticcraft.

On the website of the mod there is are some commands listed:

-getPressure(), getPressure(<side>) – Will get the pressure in the block. The side parameter is an optional parameter, and is currently only useful when getting the pressure from a Vacuum Pump, as it contains two different pressures.
-getDangerPressure() – This is a constant, it’ll be 5 bar for tier one machines, and 20 for tier two.
-getCriticalPressure() – This is a constant, it’ll be 7 bar for tier two machines, and 25 for tier two."

If I run the getPressure() thing i get the "attempt to call nil" error.

[SCREENSHOT]

Spoiler

Thanks in advance,
TIm

We've had this problem on the forums before. The problem is that it's only possible with machines (as far as I am concerned) and to read the pressure from a pipe, you need to use the Pressure Gauge Tubes (as far as I know, I do not play with the mod) and convert the redstone signal to the pressure. In the tool-tip of the pipe it says the formula.

I messed with CC 1.57 and the latest pneumatic craft myself, for some reason it hasn't worked at all ( for me ). Thus said, I'm pretty sure it's pneumatic craft's fault.

local comp = peripheral.wrap("left") --#duh, wrap a machine (specifically, I wrapped a compresser since the wiki directly says the method is available.
print( comp.getPressure() )  --#try this...

result: attempt to call nil O.o

Forum:

Every machine running on compressed air
You can get the following info from any PneumaticCraft block that runs on compressed air (including the Air Compressor, Pressure Tube):
-getPressure(), getPressure(<side>) – Will get the pressure in the block. The side parameter is an optional parameter, and is currently only useful when getting the pressure from a Vacuum Pump, as it contains two different pressures.
-getDangerPressure() – This is a constant, it’ll be 5 bar for tier one machines, and 20 for tier two.
-getCriticalPressure() – This is a constant, it’ll be 7 bar for tier two machines, and 25 for tier two.