S - N: Normal Tool Follows A Special Tool; S - N, Single Changing Arm, M4540 = 0 - HEIDENHAIN TNC 426 PB/M Technical Manual

S → N:
Normal tool follows
a special tool
S → N,
Single changing
arm, M4540 = 0
6 – 428
With this change sequence, two pocket numbers or two tool numbers must
be transferred in succession. M4520 indicates that another TOOL CALL
strobe (M4073) will follow:
7 7 7 7 With M4540 specify the sequence in which the pocket numbers are
transferred, depending on whether single or double changing arm.
First the pocket number of the old tool and the tool number zero are
transferred.
Zero means clear the spindle!
7 7 7 7 Clear the spindle and acknowledge with M4093.
Then the pocket and tool numbers of the new tool are transferred.
HEIDENHAIN Technical Manual TNC 426, TNC 430