Are the XCSDMCx7 coded magnetic switches with contact and LED compatible with the XPSAK or XPSAR Preventa modules?

No, the XCSDMCx7 coded magnetic switches are not compatible, however other Preventa Safety modules are as detailed below:

Coded magnetic switches:
 

• XCSDMC7 
• XCSDMP7
• XCSDMR7

Contact with 1 LED: 57 ohms
Contact without LED: 10 ohms 

With regard to Preventa safety modules, the maximum wiring resistance RL between modules and magnetic switches must be higher than that of the magnetic switch contacts:
 

• XPSDMBxx and XPSDMExxxx: 100 ohms => suitable for contacts with or without LED
• XPSAFxxxx: 90 ohms => suitable for contacts with or without LED
• XPSAKxxxx: 28 ohms => only suitable for contacts without LED
• XPSARxxxx: 50 ohms => only suitable for contacts without LED