Scenario 

Call the transaction /SAPTRX/EH_LIST, which exists on SCM, from ECC.

OPTION 1: Instance independent call to specified method.
In the receiving system (my example is SCM) perform the following steps:
1) SWO1
2) Enter your Z object type. e.g. ZEH_DISP
3) Add method. eg. EHList (Attributes: Dialog, Synchronous, Instance-Independent)
4) Code: eg. call transaction ‘/SAPTRX/EH_LIST’.

In the sending system (my example is ECC) perform the following code:
data: w_handle     type swo_objhnd.
      it_container type table of swcont.

      call function ‘SWO_CREATE’
        exporting
          objtype           = ‘ZEH_DISP’
          logical_system    = ‘SCM’
        importing
          object            = w_handle
        exceptions
          no_remote_objects = 1
          others            = 2.
      if sy-subrc <> 0.
        message i001(z1) with ‘No object created!’.
      endif.

      call function ‘SWO_INVOKE’
        exporting
          object    = w_handle
          verb      = ‘EHList’
        tables
          container = it_container.

OPTION 2: Instance dependent call to specified method.
In the receiving system (my example is SCM) perform the following steps:
1) SWO1
2) Enter your Z object type. e.g. ZEH_DISP
3) Add method. eg. DisplayEH (Attributes: Dialog, Synchronous)
4) Code: eg.
      DATA : w_guid TYPE /saptrx/eh_hdr-eh_guid.

      SELECT SINGLE eh_guid
        FROM /saptrx/eh_hdr
        INTO w_guid
       WHERE ao_id = object-key.

      CALL FUNCTION ‘/SAPTRX/EH_DETAILS’
        EXPORTING
          i_guid = w_guid.

In the sending system (my example is ECC) perform the following code:
data: w_handle     type swo_objhnd.
      it_container type table of swcont.

      call function ‘SWO_CREATE’
        exporting
          objtype           = ‘ZEH_DISP’
          objkey            = ‘0350000001000010’
          logical_system    = ‘SCM’
        importing
          object            = w_handle
        exceptions
          no_remote_objects = 1
          others            = 2.
      if sy-subrc <> 0.
        message i001(z1) with ‘No object created!’.
      endif.

      call function ‘SWO_INVOKE’
        exporting
          object    = w_handle
          verb      = ‘DisplayEH’
        tables
          container = it_container.

OPTION 3: Instance dependent call to default method.
1) SWO1
2) Enter your Z object type. e.g. ZEH_DISP
3) Add method. eg. DisplayEH (Attributes: Dialog, Synchronous)
4) Code: eg.
      DATA : w_guid TYPE /saptrx/eh_hdr-eh_guid.

      SELECT SINGLE eh_guid
        FROM /saptrx/eh_hdr
        INTO w_guid
       WHERE ao_id = object-key.

      CALL FUNCTION ‘/SAPTRX/EH_DETAILS’
        EXPORTING
          i_guid = w_guid.

In the sending system (my example is ECC) perform the following code:
data: w_handle     type swo_objhnd.
      it_container type table of swcont.

      call function ‘SWO_CREATE’
        exporting
          objtype           = ‘ZEH_DISP’
          objkey            = ‘0350000001000010’
          logical_system    = ‘SCM’
        importing
          object            = w_handle
        exceptions
          no_remote_objects = 1
          others            = 2.
      if sy-subrc <> 0.
        message i001(z1) with ‘No object created!’.
      endif.

      call function ‘SWO_INVOKE’
        exporting
          object    = w_handle   “No verb call
        tables
          container = it_container.