post the Macro,
If you are using M280 P3 S120 I1 that's what it does it cycles continually until M280 P3 S160 I1 to reset the probe to it's normal operating procedure this is a built in bltouch feature and not part of reprap firmware.

see my post on page 2 or 4 for testing the probing of a single point.

the name BLTouch classic has nothing to do with the 240ohm resistor being on the board, it's dependent on MFG date. you just have to look and see if the trace is on the PCB of the BLtouch

does it use a switch mounted on the rails on the back or does it have a probe?

If it has a switch on the back do you see wires coming off of that switch or have they come unplugged?

A probe will be mounted to the XY carriage that holds the hotend. Can you post pics of your printer? I have a C-bot myself, and there is also a facebook group for the C/D bots that may be able to help if it is an actual hardware issue and not firmware or controller.

@AaronGreen:

I'm still not 100% on the calibration because I don't have a conclusive idea of the config information.

If we're all using a BLTouch with the DuetWiFi, every bit of information should be the same except the bed size and carriage height parameters.

Currently, my Auto Home process checks X and Y, then when the probe touches the bed it sets off the Alarm and rams the bed indefinitely.

–------------
; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P2 ; Set firmware compatibility to look like Marlin
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X340 Y250 Z280 S0 ; Set axis maxima

; Endstops
M574 X1 Y1 Z1 S0 ; Define active low and unused microswitches
M558 P5 X0 Y0 Z1 H5 F200 T6000 ; Set Z probe type to modulated, the axes for which it is used and the probe + travel speeds
G31 X-40 Y7 Z0.9 P1 ; Set Z probe trigger value, offset and trigger height

;Z-offset (Z0.9). Higher value LOWER nozzle height
; Lower value RAISE nozzle height

M557 X10:340 Y10:240 S68 ; Define mesh grid

M307 H3 A-1 C-1 D-1 ; disable heater 3, which makes it available for use to control the BLTouch

; Drives
M569 P0 S1 ; Drive 0 goes forwards - X
M569 P1 S0 ; Drive 1 goes backwards - Y
M569 P2 S0 ; Drive 2 goes backwards - Z
M569 P3 S1 ; Drive 3 goes forwards - Extruder

M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation 16
M92 X160 Y160 Z1600 E800 ; Set steps per mm 16

M566 X600 Y420 Z12 E120 ; Set maximum instantaneous speed changes (mm/min) - (JERK)

M203 X6000 Y6000 Z500 E400 ; Set maximum speeds (mm/min)

M201 X1000 Y1000 Z1000 E250 ; Set accelerations (mm/s^2)

M204 P1000 T1000 ; Set Max acceleration for P=printing moves and T=travel moves
M906 X1600 Y1600 Z900 E1000 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Heaters
M143 S285 ; Set maximum heater temperature to 285C
;M305 P1 X101

M305 P1 T107000 B10832 C4.891620e-7 R4700 ; Set thermistor + ADC parameters for heater 0 - BED
M305 P0 T99600 B4388 C0 R4700 ; Set thermistor + ADC parameters for heater 1 - HOTEND E3d

M307 H0 P96.0, I3.285, D603.9 ;Bed
M307 H1 P1.1, I0.011, D51.5 ;Hotend pid

;M307 H1 P17.8, I0.055, D74.9 ;Hotend E3d pid

; Tools
M563 P0 D0 H1 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

; Network
M550 CLU ; Set machine name
M552 P0.0.0.0 S1 ; Enable network and acquire dynamic address via DHCP

; Fans
M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P2 S1 I0 F500 H1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Custom settings are not configured

this does not show your homeall.g and homez.g, those files are what control your homing process, and most likely the procedure needs to be changed from the G1 command to lower indefinately to G30 which will amke it stop

correct, and if you have a Z-min endstop that is in use on the printer, and the height that the nozzle needs to reach is below that Z-min endstop, you will crash into and possibly dmamage the Z-min endstop. it is better to not use one when using a probe to home and probe the bed. you are better off to use the probe to home and physically remove the Z-min endstop as it is being physically replaced and functionally replaced by the Z-probe.

It wasnt stated if you use a Z-min endstop, I am just stating the reason why you don't need one, just in case you do.

you should probably post your config, also what is your Z offset set to?

edit: missed the config link, let me look

have you tried homing X and Y only, and then moving the probe to the center of the bed then using G30 to home with the probe, I dont see G30 used in your homing files, this tells the firmware to home l;istening for the probe to trigger, and then measuring the distance from the nozzle to the bed. If you still are still you a Z endstop as well as a Z-probe, you wont be able to use compensation or probe homing as it conflicts with the use of those features.

I have them setup in custom macros on the web interface, so that If i need them they are they are easily accessed without the need to type gcodes.

here's my one question for you, and this is the main reason most of us home with the bltouch or other probing solutions in the center of the bed.

What will happen to your Z endstop when a location of a point on the bed is lower than the location of your Z endstop?

As far as the setup of the settings goes I would say you have it pretty well worked out.

free up the heater pin, asign, the heater pin for the probe, set the x/y/z offsets, set the probing dimensions(be sure that your probing dimensions compensate for the offset usually by >10 just to make sure that it will probe inside a reachable boundary), setup macro's for retract(90), deploy(10), reset(160), and self test(120)

The big thing after this is setting it all up and testing the fool out of it hooked up to make sure that you have signal fromt eh bltouch when it is in an error state(it defaults to showing triggered when in error state) and run it though its paces before you ever tell the machine to depend on it, while homing, probing etc

Ive had my bltouch setup for so long now I have to refer back to the large post i made on the original BLTouch forum post, as well. Mine is still setup on P4 as well… I just havent seen the need to change it. If i remeber correctly I made that post as a type of overall information gather for the wiki page. I'm sure some of it needs to be updated to be correct, which I think is the parts already on the wiki.

are you trying to home the printer with the Z probe?

in your homeall.g and homez.g files what is the command you use when telling the printer to dive for the Z height?

you should probably look at

http://reprap.org/wiki/G-code#G30:_Single_Z-Probe

edit:
If you are jsut testing the probe, the standard motion of the probe is to trigger and drop back down, so that it is ready to probe the next point. At the end of any probe using script you must use the Gcode to store the probe or use a macro like retractprobe.g that has the store gcode in it to retract the probe back up to get it out of the way.

As a way to test the output of the probe