THE POSSIBLE FORMAT OF C/C++ FUNCTIONS
                          FOR COMMUNICATIONS IN SCT



1. THE DEFINITIONS

   Item     - the node or unit for access in the Detector tree, or in the
              Data Base, or in the hardware device/channel.

   Name     - identification of Item in the form of the text string. The
              Name has a hierarchical structure and consist of the linear
              set of subNames; for instance:

                 “SCT.Barrel.Layer03.Loop02.Stave01.ModlTemp04”

   subName  - the local name on some hierarchical level; a subName may
              have the numerical index (see above). Every subName should
              be standard (the list of standard subNames should be created
              for ATLAS SCT).

   Stat     - State and Status (error code) of Item (i.e. Control Status
              Register – CSR of device/channel).

   Array    - a linear block of Data for Send/Take.
   Type     - the standard type of Array index (in the text form):
              - “Number”, serial number in linear structure;
              - “Scan”  , number of monitoring or testing Scan in the Run;
              - “Time”  , time in some units (say, in seconds) etc.
   From     - start index.
   Upto     - stop  index (? option: Leng – the length of Data).

   Para     - Parameter (option).


2. THE LIST OF FUNCTIONS
                                           Comments:

int SCT_OpenLink( char  *Name,  - Name of Item to link
    (option)      int   *Para); - pointer to Parameter (or NULL)

int SCT_OpenItem( char  *Name,  - Name of Item to open
                  int   *Para); - pointer to Parameter (or NULL)

int SCT_SendStat( char  *Name,  - Name of Item to send State
                  uint  *Stat); - State & Status of Item

int SCT_TakeStat( char  *Name,  - Name of Item to take State
                  uint  *Stat); - State & Status of Item

int SCT_SendData( char  *Name,  - Name of Item to send Data array
                  char  *Type,  - Array index type (Scan, Time...)
                  uint   From,  - start unit of array
                  uint   Upto,  - stop  unit of array
                  float *Data); - Pointer to the 1-st Data

int SCT_TakeData( char  *Name,  - Name of Item to take Data array
                  char  *Type,  - Array index type (Scan, Time...)
                  uint   From,  - start unit of array
                  uint   Upto,  - stop  unit of array
                  float *Data); - Pointer to the 1-st Data

int SCT_CloseItem(char  *Name,  - Name of Item to close
                  int   *Para); - pointer to Parameter (or NULL)

int SCT_CloseLink(char  *Name,  - Name of Item to link
    (option)      int   *Para); - pointer to Parameter (or NULL)


All the Functions return zero or the error code. The error code should have
the standard hierarchical structure (in according with Name hierarchy), the
standard error list should be created.


3. THE BROADCAST ACCESS ON SOME LEVEL ANS LEVEL(s) SKIPPING

3.1. The broadcast access (on some hierarchical level) may be done

- to all the Items of the same type (of the same subName);
- to all the Items of its level.

     In the first case the “non-exist” subName index may be used (in SCT DCS it
is “100” because on the any level the number of real Items is less than 100).
     For the broadcast access to all the Items of some level the standard
subName “toALL” may be used.

3.2. Sometimes it is necessary to skip some levels in the Item Name. In this
case the special empty-name “NoNN” may be used, where NN is the level number.




   S.G.Basiladze                basilad@mail.cern.ch