Call and declaration of the substation

The complete functionality of a substation is encapsulated in the FB_IEC870_5_104Slave function block. An instance can be used to establish a connection to the master. For a further connection, declare a further instance and transmit the same server handle (hServer variable) to this second instance, or use the FB_IEC870_5-104SlaveGrp function block (recommended). You must set the IP address to match the IP address of your target system

Insert the following PLC code in the declaration part of MAIN:

PROGRAM MAIN
VAR 
AODB : ARRAY[0..49] OF ST_IEC870_5_101AODBEntry; 

init : BOOL := TRUE; 
initError : UDINT; 

inputs AT%IB0 : ARRAY[0..2999] OF BYTE; 
outputs AT%QB0 : ARRAY[0..2999] OF BYTE; 
memory AT%MB0 : ARRAY[0..2999] OF BYTE; 
data : ARRAY[0..2999] OF BYTE; 

bEnable : BOOL := TRUE; 
hServer : T_HSERVER; 
server : FB_IEC870_5_104Slave; 

END_VAR 

and the instance is called in the program part:

IF init THEN 
init := FALSE; 
... 


F_CreateServerHnd( '', '127.0.0.1'(* change this! *), 2404, nMode := LISTEN_MODE_CLOSEALL OR CONNECT_MODE_ENABLEDBG, bEnable, hServer ); 

ELSE 
server( pInputs := ADR( inputs ), 
cbInputs := SIZEOF( inputs ), 
pOutputs := ADR( outputs ), 
cbOutputs := SIZEOF( outputs ), 
pMemory := ADR( memory ), 
cbMemory := SIZEOF( memory ), 
pData := ADR( data ), 
cbData := SIZEOF( data ), 
pAOEntries := ADR( AODB ), 
cbAOEntries := SIZEOF( AODB ), 
hServer := hServer, 
bEnable := bEnable ); 
END_IF