Defining and configuring an application object database of controling station
Application objects = single points, double points, measured values, short floating point values, etc.
In this sample, the commands were configured so that the process data in the control direction (commands) are in the same memory area but on a different byte/bit offset than the data of the information in the monitoring direction. If required the commands may have the same byte/bit offset as the information in monitoring direction.
Sample:
C_SC_NA_1 with IOA = 10 on the same byte/bit offset as M_SP_NA_1 with IOA = 100 (both byte offset = 100 and bit offset = 0). If the value of M_SP_NA_1 changes, a new C_SC_NA_1 command is triggered.
As an example we will configure the following application objects as part of the introductory project:
ASDU identifier | Object address | Group configuration parameter | Base time multiplier | PLC process data area | Offset | Offset | Process data width in the TwinCAT PLC |
|---|---|---|---|---|---|---|---|
M_SP_NA_1 | 100 | General interrogation | 0 | Flags | 100 | 0 | 1-bit |
M_SP_TA_1 | 101 | General interrogation | 0 | Flags | 100 | 1 | 1-bit |
M_SP_TB_1 | 102 | General interrogation | 0 | Flags | 100 | 2 | 1-bit |
M_DP_NA_1 | 200 | General interrogation | 0 | Flags | 200 | 0 | 2 bits |
M_DP_TA_1 | 201 | General interrogation | 0 | Flags | 200 | 2 | 2 bits |
M_DP_TB_1 | 202 | General interrogation | 0 | Flags | 200 | 4 | 2 bits |
M_ST_NA_1 | 300 | General interrogation | 0 | Flags | 300 | 0 | 1 byte |
M_ST_TA_1 | 301 | General interrogation | 0 | Flags | 301 | 0 | 1 byte |
M_ST_TB_1 | 302 | General interrogation | 0 | Flags | 302 | 0 | 1 byte |
M_BO_NA_1 | 400 | General interrogation | 0 | Flags | 400 | 0 | 4 bytes |
M_BO_TA_1 | 401 | General interrogation | 0 | Flags | 404 | 0 | 4 bytes |
M_BO_TB_1 | 402 | General interrogation | 0 | Flags | 408 | 0 | 4 bytes |
M_ME_NA_1 | 500 | General interrogation | 0 | Flags | 500 | 0 | 2 bytes |
M_ME_TA_1 | 501 | General interrogation | 0 | Flags | 502 | 0 | 2 bytes |
M_ME_TD_1 | 502 | General interrogation | 0 | Flags | 504 | 0 | 2 bytes |
M_ME_NB_1 | 600 | General interrogation | 0 | Flags | 600 | 0 | 2 bytes |
M_ME_TB_1 | 601 | General interrogation | 0 | Flags | 602 | 0 | 2 bytes |
M_ME_TE_1 | 602 | General interrogation | 0 | Flags | 604 | 0 | 2 bytes |
M_ME_NC_1 | 700 | General interrogation | 0 | Flags | 700 | 0 | 4 bytes |
M_ME_TC_1 | 701 | General interrogation | 0 | Flags | 704 | 0 | 4 bytes |
M_ME_TF_1 | 702 | General interrogation | 0 | Flags | 708 | 0 | 4 bytes |
M_IT_NA_1 | 800 | General counter interrogation and Mode A (local freeze with spontaneous transmission every 15 s) | 0 | Flags | 800 | 0 | 4 bytes |
M_IT_TA_1 | 801 | General counter interrogation and Mode A (local freeze with spontaneous transmission every 15 s) | 0 | Flags | 804 | 0 | 4 bytes |
M_IT_TB_1 | 802 | General counter interrogation and Mode A (local freeze with spontaneous transmission every 15 s) | 0 | Flags | 808 | 0 | 4 bytes |
Commands |
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C_SC_NA_1 | 10 | - | 0 | Flags | 2100 | 0 | 1-bit |
C_SC_NA_1 | 11 | - | 0 | Flags | 2100 | 1 | 1-bit |
C_SC_TA_1 | 12 | - | 0 | Flags | 2100 | 2 | 1-bit |
C_DC_NA_1 | 20 | - | 0 | Flags | 2200 | 0 | 2-bit |
C_DC_NA_1 | 21 | - | 0 | Flags | 2200 | 2 | 2-bit |
C_DC_TA_1 | 22 | - | 0 | Flags | 2200 | 4 | 2-bit |
C_BO_NA_1 | 40 | - | 0 | Flags | 2400 | 0 | 4 bytes |
C_BO_NA_1 | 41 | - | 0 | Flags | 2404 | 0 | 4 bytes |
C_BO_TA_1 | 42 | - | 0 | Flags | 2408 | 0 | 4 bytes |
C_SE_NA_1 | 50 | - | 0 | Flags | 2500 | 0 | 2 bytes |
C_SE_NA_1 | 51 | - | 0 | Flags | 2502 | 0 | 2 bytes |
C_SE_TA_1 | 52 | - | 0 | Flags | 2504 | 0 | 2 bytes |
C_SE_NB_1 | 60 | - | 0 | Flags | 2600 | 0 | 2 bytes |
C_SE_NB_1 | 61 | - | 0 | Flags | 2602 | 0 | 2 bytes |
C_SE_TB_1 | 62 | - | 0 | Flags | 2604 | 0 | 2 bytes |
C_SE_NC_1 | 70 | - | 0 | Flags | 2700 | 0 | 4 bytes |
C_SE_NC_1 | 71 | - | 0 | Flags | 2704 | 0 | 4 bytes |
C_SE_TC_1 | 72 | - | 0 | Flags | 2708 | 0 | 4 bytes |
Declaring a database variable
The application object database is an array variable of type ST_IEC870_5_101AODBEntry. Each array element corresponds to an application object. The array elements are not manipulated directly but through specially provided functions and a database handle (table handle). The database handle must be initialized via a F_iecCreateTableHnd function call before it can be used. During this process the array elements are linked as a hash table. With a larger number of data points the hash table enables faster access to individual data points.
The maximum number of application objects is freely selectable and is only limited by the available memory. During PLC programming you have to specify a constant maximum number. The maximum number of application objects cannot be changed at runtime. In our sample 50 application objects are declared. This number is sufficient for most applications. Please note that many application objects require adequate memory and runtime resources.
Define the following variables in P_MAIN_LowSpeed:
PROGRAM P_MAIN_LowSpeed
VAR
AODB : ARRAY[0..49] OF ST_IEC870_5_101AODBEntry;
hTable : T_HAODBTable;
END_VARConfiguring application objects
The required application objects are configured during program runtime. Amongst other things, the object type (M_SP_NA_1, M_DP_NA_1, M_ST_NA_1, etc.), the common ASDU address, the object address and further object parameters are defined during the configuration.
After initialization of the database handle is the application object database (database array) is empty and must be filled with the required data (data points). The configuration of the data points in the central station must correspond to the configuration of the data points in the substation! This means that data points configured in the central station must be of the same type, with the same common ASDU address and with the same information object address as in the substation. Other parameters such as the mapping range, byte and bit offset can be configured as desired.
The following functions are available for manipulating the application database:
Function | Description |
|---|---|
F_iecCreateTableHnd
| Initializes the hash table handle |
F_iecAddTableEntry
| Configures and inserts a new hash table entry |
F_iecRemoveTableEntry
| Removes a hash table entry |
F_iecLookupTableEntry
| Checks whether a certain hash table entry exists |
F_iecGetPosOfTableEntry
| Determines the linear position of a hash table entry |
The database handle must be transmitted to the function via VAR_IN_OUT. Configuration is usually carried out once during PLC program start-up via an Init routine.
To configure the application objects at program start, the following PLC code is added to P_MAIN_LowSpeed:
PROGRAM P_MAIN_LowSpeed
VAR
AODB : ARRAY[0..49] OF ST_IEC870_5_101AODBEntry;
hTable : T_HAODBTable;
init : BOOL := TRUE;
initError : UDINT;
asduAddr : UDINT := 7;
END_VARIF init THEN
init := FALSE;
initError := F_iecCreateTableHnd( ADR( AODB ), SIZEOF( AODB ), hTable );
IF initError <> 0 THEN
ADSLOGSTR( ADSLOG_MSGTYPE_HINT OR ADSLOG_MSGTYPE_LOG,
'F_iecCreateTableHnd() error: %s',
DWORD_TO_HEXSTR( initError, 8, FALSE ) );
RETURN;
END_IF
(* Monitored Single Points *)
initError := F_iecAddTableEntry( M_SP_NA_1, asduAddr, 100, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 100, 0, 0, hTable );
initError := F_iecAddTableEntry( M_SP_NA_1, asduAddr, 101, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 100, 1, 0, hTable );
initError := F_iecAddTableEntry( M_SP_TB_1, asduAddr, 102, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 100, 2, 0, hTable );
(* Double Points*)
initError := F_iecAddTableEntry( M_DP_NA_1, asduAddr, 200, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 200, 0, 0, hTable );
initError := F_iecAddTableEntry( M_DP_NA_1, asduAddr, 201, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 200, 2, 0, hTable );
initError := F_iecAddTableEntry( M_DP_TB_1, asduAddr, 202, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 200, 4, 0, hTable );
(* Regulating step value *)
initError := F_iecAddTableEntry( M_ST_NA_1, asduAddr, 300, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 300, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ST_NA_1, asduAddr, 301, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 301, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ST_TB_1, asduAddr, 302, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 302, 0, 0, hTable );
(* 32 bit string *)
initError := F_iecAddTableEntry( M_BO_NA_1, asduAddr, 400, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 400, 0, 0, hTable );
initError := F_iecAddTableEntry( M_BO_NA_1, asduAddr, 401, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 404, 0, 0, hTable );
initError := F_iecAddTableEntry( M_BO_TB_1, asduAddr, 402, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 408, 0, 0, hTable );
(* Measured value, normalized value *)
initError := F_iecAddTableEntry( M_ME_NA_1, asduAddr, 500, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 500, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ME_NA_1, asduAddr, 501, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 502, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ME_TD_1, asduAddr, 502, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 504, 0, 0, hTable );
(* Measured value, scaled value *)
initError := F_iecAddTableEntry( M_ME_NB_1, asduAddr, 600, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 600, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ME_NB_1, asduAddr, 601, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 602, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ME_TE_1, asduAddr, 602, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 604, 0, 0, hTable );
(* Measured value , short floating point value *)
initError := F_iecAddTableEntry( M_ME_NC_1, asduAddr, 700, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 700, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ME_NC_1, asduAddr, 701, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 704, 0, 0, hTable );
initError := F_iecAddTableEntry( M_ME_TF_1, asduAddr, 702, IEC870_GRP_INROGEN, 0, MAP_AREA_MEMORY, 708, 0, 0, hTable );
(* Integrated totals *)
initError := F_iecAddTableEntry( M_IT_NA_1, asduAddr, 800, IEC870_GRP_REQCOGEN, 0, MAP_AREA_MEMORY, 800, 0, 0, hTable );
initError := F_iecAddTableEntry( M_IT_NA_1, asduAddr, 801, IEC870_GRP_REQCOGEN, 0, MAP_AREA_MEMORY, 804, 0, 0, hTable );
initError := F_iecAddTableEntry( M_IT_TB_1, asduAddr, 802, IEC870_GRP_REQCOGEN, 0, MAP_AREA_MEMORY, 808, 0, 0, hTable );
(* Single commands *)
initError := F_iecAddTableEntry( C_SC_NA_1, asduAddr, 10, 0, 0, MAP_AREA_MEMORY, 2100, 0, 0, hTable );
initError := F_iecAddTableEntry( C_SC_NA_1, asduAddr, 11, 0, 0, MAP_AREA_MEMORY, 2100, 1, 0, hTable );
initError := F_iecAddTableEntry( C_SC_TA_1, asduAddr, 12, 0, 0, MAP_AREA_MEMORY, 2100, 2, 0, hTable );
(* Double commands *)
initError := F_iecAddTableEntry( C_DC_NA_1, asduAddr, 20, 0, 0, MAP_AREA_MEMORY, 2200, 0, 0, hTable );
initError := F_iecAddTableEntry( C_DC_NA_1, asduAddr, 21, 0, 0, MAP_AREA_MEMORY, 2200, 2, 0, hTable );
initError := F_iecAddTableEntry( C_DC_TA_1, asduAddr, 22, 0, 0, MAP_AREA_MEMORY, 2200, 4, 0, hTable );
(* 32 bit string commands *)
initError := F_iecAddTableEntry( C_BO_NA_1, asduAddr, 40, 0, 0, MAP_AREA_MEMORY, 2400, 0, 0, hTable );
initError := F_iecAddTableEntry( C_BO_NA_1, asduAddr, 41, 0, 0, MAP_AREA_MEMORY, 2404, 0, 0, hTable );
initError := F_iecAddTableEntry( C_BO_TA_1, asduAddr, 42, 0, 0, MAP_AREA_MEMORY, 2408, 0, 0, hTable );
(* Set point, normalized values*)
initError := F_iecAddTableEntry( C_SE_NA_1, asduAddr, 50, 0, 0, MAP_AREA_MEMORY, 2500, 0, 0, hTable );
initError := F_iecAddTableEntry( C_SE_NA_1, asduAddr, 51, 0, 0, MAP_AREA_MEMORY, 2502, 0, 0, hTable );
initError := F_iecAddTableEntry( C_SE_TA_1, asduAddr, 52, 0, 0, MAP_AREA_MEMORY, 2504, 0, 0, hTable );
(* Set point, scaled values *)
initError := F_iecAddTableEntry( C_SE_NB_1, asduAddr, 60, 0, 0, MAP_AREA_MEMORY, 2600, 0, 0, hTable );
initError := F_iecAddTableEntry( C_SE_NB_1, asduAddr, 61, 0, 0, MAP_AREA_MEMORY, 2602, 0, 0, hTable );
initError := F_iecAddTableEntry( C_SE_TB_1, asduAddr, 62, 0, 0, MAP_AREA_MEMORY, 2604, 0, 0, hTable );
(* Set point, short floating point values *)
initError := F_iecAddTableEntry( C_SE_NC_1, asduAddr, 70, 0, 0, MAP_AREA_MEMORY, 2700, 0, 0, hTable );
initError := F_iecAddTableEntry( C_SE_NC_1, asduAddr, 71, 0, 0, MAP_AREA_MEMORY, 2704, 0, 0, hTable );
initError := F_iecAddTableEntry( C_SE_TC_1, asduAddr, 72, 0, 0, MAP_AREA_MEMORY, 2708, 0, 0, hTable );
END_IF