*+
*  Name:
*     ARY_TCB

*  Purpose:
*     Define ARY_ system Error Tracing Control Block (TCB).

*  Language:
*     Starlink Fortran 77

*  Type of Module:
*     Global variables include file.

*  Description:
*     This file defines global variables which control the reporting of
*     error tracing messages via the ARY1_TRACE routine which is called
*     by most other routines in the ARY_ system.

*  Authors:
*     RFWS: R.F. Warren-Smith (STARLINK)
*     {enter_new_authors_here}

*  History:
*     22-NOV-1989 (RFWS):
*        Original version.
*     {enter_changes_here}

*-

*  Global Variables:

*  Error tracing flag:
*  ==================
*  This logical flag controls whether the ARY1_TRACE routine actually
*  reports a message. This routine is called whenever another ARY_
*  system routine exits as a result of an error occurring within itself
*  or a lower level routine which it calls. This results in a series of
*  messages showing the sequence of routines which have exited
*  prematurely as a result of the error. The TCB_ETFLG flag controls
*  whether this internal diagnostic information is actually produced.
*  Its initial value is established by the ARY1_INIT block data
*  routine; its subsequent value is controlled by calls to ARY_TRACE.
      LOGICAL TCB_ETFLG

*  Non-character data.
      COMMON /ARY1_TCB1/ TCB_ETFLG

*.
