where is Z max? (1 reply)

Hi,

I have a Zonestar (aliexpress DIY printer) with a sanguinololu board.
I'm using a inductive sensor as z-probe.
I have the probe connected to Z-min(pin 20) and mounted a NC switch at the top as Z-Max and connected to pin 16.
When i trigger the endstop it shows in the debugging

M43 P16 W
Watching pins
PIN:  16   Port: C0        SCL
PIN:  16   Port: C0        SCL

But when it would not show up when i M119

M119*31
Reporting endstop status
x_min: open
y_min: open
z_probe: open

configuration.h

//===========================================================================
//============================== Endstop Settings ===========================
//===========================================================================

// @section homing

// Specify here all the endstop connectors that are connected to any endstop or probe.
// Almost all printers will be using one per axis. Probes will use one or more of the
// extra connectors. Leave undefined any used for non-endstop and non-probe purposes.
#define USE_XMIN_PLUG
#define USE_YMIN_PLUG
#define USE_ZMIN_PLUG
//#define USE_XMAX_PLUG
//#define USE_YMAX_PLUG
#define USE_ZMAX_PLUG

pins_sanguinololu_12.h
//
// Limit Switches
//
#define X_STOP_PIN         18
#define Y_STOP_PIN         19
#define Z_STOP_PIN         20

// my own code
#define X_MIN_PIN          18
#define Y_MIN_PIN          19
#define Z_MAX_PIN          16

#ifndef Z_MIN_PROBE_PIN
  #define Z_MIN_PROBE_PIN  20
#endif

//endof my own code

M43

PIN:  15   Port: D7        X_STEP_PIN                  protected
PIN:  16   Port: C0        SCL                         Input  = 0
PIN:  17   Port: C1        SDA                         Input  = 0
PIN:  18   Port: C2        X_MIN_PIN                   protected
.                          X_STOP_PIN                  protected
 PIN:  19   Port: C3        Y_MIN_PIN                   protected
 .                          Y_STOP_PIN                  protected
 PIN:  20   Port: C4        Z_MAX_PIN                   protected
.                          Z_MIN_PROBE_PIN             protected
.                          Z_STOP_PIN                  protected

What am i missing/doing wrong? where do i "activate" the Z-max swtich?