Path or time-related pre-output of H functions (P-CHAN-00107)


Path or time-related pre-output of H functions


This parameter is used in connection with H functions

  • of synchronisation types MET_SVS, MET_MOS and MEP_SVS, MEP_MOS. The lead time is specified for MET_SVS, MET_MOS and the lead distance for the MEP_SVS or MEP_MOS type.
  • of synchronisation types MOS, MVS_SVS, MVS_SNS, MNS_SNS, MOS_TS and the ‘microwebs’ function which requires a separate license (see [FCT-C1]). Path-related parameters make sense here.

The field index 'i' defines the number of the associated H function. The value of h_pre_outp[i] defines the path and time-related output point before actual processing of the H function on the path.


h_pre_outp[i] where i = 0 999 (maximum number of H functions, application-specific)

Data type


Data range

0 ... MAX(UNS32)


0.1µm or µs

Default value



The pre-output value can also be defined in the NC program [PROG//Chapter V.G. variables].


If the synchronisation type of an H function is later changed into one which requires no pre-output value, h_pre_outp[i] must be assigned to 0. Otherwise, a license error is generated in case of microwebs if this function is not licensed or not enabled (see P-STUP-00060).

Parameterisation example:

User-specific H functions H96 and H98 must be output to the PLC 10 mm before reaching the synchronisation position in the block sequence.

The output of the user specific H functions H97 and H99 to the PLC must be executed 40 milliseconds before reaching the time of synchronisation in the block sequence.


# Definition of H functions and synchronisation types

# ============================================

h_synch[96]                           0x01000000    MEP_SVS

h_synch[97]                           0x02000000    MET_SVS

h_synch[98]                           0x00100000    MEP_MOS

h_synch[99]                           0x00200000    MET_MOS


# Definition of pre-output path, pre-output time


h_pre_outp[96]                     100000     in 0.1µm

h_pre_outp[97]                       40000     in µs

h_pre_outp[98]                     100000    in 0.1µm

h_pre_outp[99]                       40000    in µs

For further examples see section Synchronisation types of M functions (P-CHAN-00041).