Post by scoob on ModbusFB - Slow Response Time ^{CODESYS Forge talk (Post)}
Hello, I have been trying to use the ModbusFB functions so I can put some code into libraries, but it seems to be very slow for me. I have a Modbus device with 100ms registers. I previously setup 10 channels in the 'traditional' Modbus Slave with channels and mappings - and set a cyclic trigger at 100ms - this worked fine. I then tried the ModbusFB example, and setup reading the same 10 blocks of modbus addresses, copying the example and putting all of the requests into an array and triggering the requests sequentially. I timed how long the requests are taking to get round to each one, and it is around 1s 450ms. How do I speed this up to match the cyclic time? IF NOT(init) THEN init := TRUE; // Set the required IP address: ipAddress[0] := 192; ipAddress[1] := 168; ipAddress[2] := 1; ipAddress[3] := 10; // Pass the required IP address to the clinet FB: client_NetworkSwitch.aIPaddr := ipAddress; client_NetworkSwitch.udiLogOptions := (ModbusFB.LoggingOptions.ClientConnectDisconnect OR ModbusFB.LoggingOptions.ClientReceivedValidReplies); // Try to connect the client client_NetworkSwitch(xConnect:=TRUE); // Configure all the channels to read connecting them to the client: portStatus_Request(rClient := client_NetworkSwitch, uiStartItem := 4096, uiQuantity := 32, pData := ADR(portStatus), udiReplyTimeout := udiReplyTimeout); portSpeed_Request(rClient := client_NetworkSwitch, uiStartItem := 4352, uiQuantity := 32, pData := ADR(portSpeed)); flowControl_Request(rClient := client_NetworkSwitch, uiStartItem := 4608, uiQuantity := 32, pData := ADR(flowControl)); linkUpCounter_Request(rClient := client_NetworkSwitch, uiStartItem := 5888, uiQuantity := 32, pData := ADR(linkUpCounter)); txPacketCounter1_Request(rClient := client_NetworkSwitch, uiStartItem := 8192, uiQuantity := 100, pData := ADR(txPacketCounter1)); txPacketCounter2_Request(rClient := client_NetworkSwitch, uiStartItem := 8292, uiQuantity := 28, pData := ADR(txPacketCounter2)); rxPacketCounter1_Request(rClient := client_NetworkSwitch, uiStartItem := 8448, uiQuantity := 100, pData := ADR(rxPacketCounter1)); rxPacketCounter2_Request(rClient := client_NetworkSwitch, uiStartItem := 8548, uiQuantity := 28, pData := ADR(rxPacketCounter2)); txErrors_Request(rClient := client_NetworkSwitch, uiStartItem := 8704, uiQuantity := 64, pData := ADR(txErrors)); rxErrors_Request(rClient := client_NetworkSwitch, uiStartItem := 8960, uiQuantity := 64, pData := ADR(rxErrors)); // Trigger all client requests initially FOR clientRequestsCnt := 0 TO (SIZEOF(clientRequests)/SIZEOF(clientRequests[0]))-1 DO pClientRequest := clientRequests[clientRequestsCnt]; pClientRequest^.xExecute := TRUE; END_FOR // Prepare sequential trigger / control of client requests. clientRequestsCnt := 0; pClientRequest := clientRequests[clientRequestsCnt]; END_IF // Call the client to do request processing: client_NetworkSwitch(); // Now we trigger client request sequentially ... IF NOT pClientRequest^.xExecute AND NOT pClientRequest^.xDone AND run AND client_NetworkSwitch.xConnected THEN pClientRequest^.xExecute := TRUE; END_IF // .. and check result/error IF pClientRequest^.xExecute AND run AND client_NetworkSwitch.xConnected THEN IF pClientRequest^.xDone THEN // Prepare next trigger of client request (a rising edge of xExecute) pClientRequest^.xExecute := FALSE; IF clientRequestsCnt < SIZEOF(clientRequests)/SIZEOF(clientRequests[0])-1 THEN // next client request clientRequestsCnt := clientRequestsCnt + 1; ELSE clientRequestsIterationCounter := clientRequestsIterationCounter + 1; clientRequestsCnt := 0; END_IF pClientRequest := clientRequests[clientRequestsCnt]; END_IF END_IF I did try a semi-coded way using the IoDrvModbusTCP library, and setting the slave com settings, then 10 commands and 10 requests, then using a TP on xDone as a pause, before triggering another request - this is time the delay is around 120ms - so the device is fine with the speed, just something I am doing wrong in the ModbusFB method I am sure.
Last updated: 2024-04-26

Post by alessandro on SysMemCmp SysMemCpy ^{CODESYS Forge talk (Post)}
VAR Data1:ARRAY[1..10] OF SINT ; Data2:ARRAY[1..10] OF SINT ; Data3:ARRAY[1..10] OF SINT ; Data4:ARRAY[1..10] OF SINT ; ex_1 : BOOL ; ex_2 : BOOL ; enable : BOOL :=0 ; END_VAR // PROGRAM // The scope of this example is compare and copy the values of two ARRAY only if some value is different using SysMemCmp and SysMemCpy. // In this 2 example we don't use a FOR cicle for do this, and pBuffer1 and pBuffer2 is just a pointer to ARRAY. See details in Library util.SysMem of Codesys // The compare funcion util.SysMem.SysMemCmp is bidirectional if Data1 chanege respect Data2 ex_1 go to 1 and if Data2 change respect Data1 also // but the copy function util.SysMem.SysMemCpy work only from source ARRAY pSrc:=ADR(Data1) to destination ARRAY pDest:=ADR(Data2) // Example 1 Full ARRAY compare and copy // This compare 2 different equal ARRAY and if there is some difference ex_1 go to 1 and if you give enable he copy Data1 in Data2 ex_1 := TO_BOOL(util.SysMem.SysMemCmp(pBuffer1:=ADR(Data1), pBuffer2:=ADR(Data2), udiCount:=SIZEOF(Data1))); IF ex_1 AND enable THEN util.SysMem.SysMemCpy(pDest:=ADR(Data2), pSrc:=ADR(Data1), udiCount:=SIZEOF(Data1)); END_IF // Example 2 Only selected area of the ARRAY compare and copy // This compare 2 different equal ARRAY starting from position number [3] for 4 byte in this case start at position [3] and finish at position number [6] // and if there is some difference only in area [3..6] of the ARRAY ex_2 go to 1 if you give enalbe he copy Data3[3..6] in Data4[3..6] // if something change in other array position[0..2] or [7..10] are ingnored ex_2 := TO_BOOL(util.SysMem.SysMemCmp(pBuffer1:=ADR(Data3[3]), pBuffer2:=ADR(Data4[3]), udiCount:=4)); IF ex_2 AND enable THEN util.SysMem.SysMemCpy(pDest:=ADR(Data4[3]), pSrc:=ADR(Data3[3]), udiCount:=4); END_IF // Attention udiCount input is intended in <byte> in the example 1 I pass to udiCount:=SIZEOF(Data1) for compare and copy the intere ARRAY and // SIZEOF pass the size of intere ARRAY in byte to the function input, in this 2 examples I used variable type SINT each one occupie 1 byte and one position in the ARRAY // and in the example 2 I pass udiCount:=4 for compare and copy only 4 position of Data3/4[3..6] if you want to extend this example and use it for an ARRAY OF WORD // remember that each WORD will occupe 2 byte (16 bit) and you will have to pass udiCount:=SIZEOF(Data1) if you need to compare intere ARRAY example 1 // but need udiCount:=(42) for the example 2 because need to compare and copy 4 word each occupie 2 byte (16 bit). // For REAL (32 bit) need udiCount:=SIZEOF(44) for LREAL or (64 bit) need udiCount:=SIZEOF(416) // a good rule is calculate the dimension of the ARRAY in byte without empty space at the end, multiple of data type number for variable bigger then 8 bit // Example : If you want to create an ARRAY for 5 REAL (32 bit) each occupie 4 byte the correct size is ARRAY[0..19] OF REAL 54=20 position. // NOTE : In the example the position of compare function util.SysMem.SysMemCmp is first and the copy function util.SysMem.SysMemCpy inside the IF is after // in one cycle of the program the two array is compared and if there is some difference and enable are copied. // If you move util.SysMem.SysMemCmp after the IF cycle he will copare the ARRAY in the current cycle but the copy of the value will do in the next cycle.</byte>
Last updated: 2025-10-24

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