M or K that is the question. (Loc101Mxxx vs Loc101Kxxx for pneumatic cylinders)

[maj9bj]

I'm slightly confused about what letter to use to identify the name of the pneumatic cylinder. In the BMK documentation there is an information M letter should be used for mechanical components which pneumatic cylinder is.

But for example in digital machine the M letter is used only for axis or robot (e.g. 101M711_Robot) and pneumatic cylinders and grippers are marked as K (e.g. 101K401_Gripper). I also saw many other projects and the naming is always different.

Can someone explain me what is the right naming or link some screenshot from documentation, where it is mentioned?

[SteffenR- · Accepted solution]

(DIN) EN IEC 81346-2 lists a table with letters for different devices:

• M = all mechanical movements = axis, cylinders, etc.
• K = converting an input signal to another output signal
• B = detecting and showing information
• Q = change of energy
• T = transformator, inverter
• S = detecting human input
• A = not allowed anymore

That means

• Axis/Drives:
  • motor: M
  • inverter: T
  • brake: Q
• Pneumatic cylinder:
  • Moving cylinder: M
  • Relais that is transforming the 24V signal from PLC into switching compressed air: K
  • Valve: Q
  • End position sensor: B

In Control plus Studio we are connecting the peripherals with objects and Control plus Studio automatically generates the item designator into the HMI. The fieldbus devices and I/O are the axis controller (T) and PLC output (K). That means the HMI shows these information. More universal regarding the norm would be a M for both in the HMI, but then you must edit the item designator of every object/unit manually.

The name of the units in the application you can choose by yourself. I prefer T for axis object and K for BasMove to be consistent with the peripheral names (and to be consistent with the HMI if you use the automatical generated item designator).

PS: Example project Digital Machine will be updated regarding this topic.