Siemens sinumerik 840D sl Function Manual page 142

Detailed description
2.1 "Gantry axes" function
When below the warning limit, the message and interface signal will automatically be
cancelled.
When MD37110 = 0 the message will be disabled.
Gantry trip limit
Alarm 10653 "error limit exceeded" will be signaled when the machine's maximum
permissible actual position values are exceeded:
MD37120 $MA_GANTRY_POS_TOL_ERROR (gantry trip limit)
In order to prevent any damage to the machines, the gantry axes will be immediately shut
down via the break ramp.
The value of MD37120 is applied when the gantry grouping is synchronized.
The alarm must be acknowledged with "RESET".
In addition, the following interface signal will be output to the PLC:
DB31, ... DBX101.2 (gantry trip limit exceeded)
If the gantry axis grouping has not yet been synchronized, the limit value for the gantry trip
limit is derived from the machine data:
MD37130 $MA_GANTRY_POS_TOL_REF (gantry trip limit)
Gantry shutdown limit exceeded is also activated if the gantry grouping is jammed (no servo
enable, gantry grouping in "Hold" state).
The monitoring functions are deactivated while the grouping is operating in "Follow-up"
mode.
Extended monitoring
An extended monitoring can be activated with the machine data:
MD37150 $MA_GANTRY_FUNCTION_MASK (gantry functions)
Effect:
An offset between the master and slave axis resulting from follow-up or Break_Up 1 is
included in the synchronous operation difference and triggers an alarm when the
corresponding warning or error limits are reached.
After power-up, extended monitoring is activated when the first reference point or
synchronization (absolute encoder) is reached, irrespective of the axis status: e.g. RFG, NF,
reference point approach, etc.
10
Special functions: Gantry Axes (G1)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0