Tool change without dialog

Hi,
I have a textile cutter that has only two tools. The rotary blade and the pen. Both are fixed to the head. There is an offset between the two that is taken care of by the offset table.
The question is how do I do a tool change from Gcode without invoking the Dialog

This is the snippet from the gcode file

N0080 o<init_code.ngc> call 
N0090 (Part: Cutting Table Test Cut - 28-01-2020)
N0100 (Operation: No Offset, Pen, T200: Pen, 1 mm Deep)
N0110 M6 T200  (Pen)
N0120 G43 H200
N0130 F200.0
N0140 G56

M61 Qn is changing the active tool number, without dialog or toolchange position.

I don't know if this is a good solution or a hack. I put this in the post_gui.ha and it works just fine.

# ---toolchange signals for custom tool changer-

net tool-number <= iocontrol.0.tool-prep-number
#net tool-change-request <= iocontrol.0.tool-change
net tool-change-confirmed => iocontrol.0.tool-changed <= iocontrol.0.tool-change
#net tool-prepare-request <= iocontrol.0.tool-prepare
net tool-prepare-confirmed => iocontrol.0.tool-prepared <= iocontrol.0.tool-prepare

You can set this pin permanently to 1:

hal_manualtoolchange.change_button

(when using this component.
 Gmoccapy has a similar pin in curremt master)

That is like you would have the confirm buttom pressed permanently.

IMHO better solution is to use M61 instead of M6, so if you want or not to take note of a tool change you just can use M61 or M6

Norbert 

I don't even know if I need to do a tool change in the Gcode file. The offsets are held in the G55 and G56 parameters. Both tools are fixed to the head and the gcode makes use of M3, M4 and M5 to control valves that operate pneumatic cylinders to put either the pen or the knife down. Before the pen or knife is used the G55 or G56 code is called.
What would be the affect if I don't load a tool at all?

Keep in mind that there are no real tool changes as both the tools on the machine are attached to the head permanently and are activated by M codes. I use G10 to setup the offsets in the beginning of the gcode file.
I adopted this method from the Sheetcam post process and the way the machine worked with Mach3 installed before the upgrade to Linuxcnc.