# CODESYS communicatioins with IO-Link master 765-45x **URL:** https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884 **Category:** CODESYS **Tags:** codesys **Created:** [May 28, 2025, 4:16am UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884 "2025-05-28T04:16:45Z") **Posts on this page:** 7 **Page:** 1
### Author: ![Justin](https://avatars.discourse-cdn.com/v4/letter/j/3ab097/32.png) [@Justin](https://www.wago.community/u/Justin) #### Post date: [May 28, 2025, 4:16am UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884/1 "2025-05-28T04:16:45Z")
We are using the 765-4501 as an IO-Link master, connected by EtherNet/IP to a PFC200 (750-8217). Logic is programmed in CODESYS (V3.5 SP19 Patch 7). We know the set of IO-Link slave devices that will be connected to the IO-Link master, but not how many of each type of device will be connected or which ports each will use. We have been unable to find a CODESYS library to facilitate communications between the PFC and the 765-4501 (unlike e.g. the 750-657) and consequently have two questions: 1. How can we identify IO-Link device details for each connected port? 2. How can we write to selected settings of IO-Link devices for each connected port? ---
### Author: ![MikePsaltis](https://sea2.discourse-cdn.com/flex016/user_avatar/www.wago.community/mikepsaltis/32/47_2.png) [@MikePsaltis](https://www.wago.community/u/MikePsaltis) #### Post date: [May 28, 2025, 2:42pm UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884/2 "2025-05-28T14:42:50Z")
Hi Justin, You can do this with ISDU read/writes via an EthernetIP Explicit Message Function block. I am working on a function block that can configure the ports of a WAGO 765-1703 DIO Hub (IOL Device). Here is what I have so far in this FB: 1. Check that the EIP Connection is OK 2. Check that the device that is connected to the specified port is a “765-1703”. In this case I perform an ISDU read for Index 19. 3. I can then read and write to Index 64 (16#40) to set the each port as an input or output. ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/8/80b05b65596aecf243c2508dbf054baa55d2356a.png) You could all adapt this FB to read Index 19 for each port to get data about what device is connected. I believe that this is an IO-Link standard Index, but would need to check the manual of you IOL devices. For this case, this is what the instance of my function block looks like. I pass it the EIP device name, a port number and can trigger reads/writes to the DIO Hub. ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/9/9ec445cccbd410d38c8edb8ea46807d54609933f.png) I added the development logic to a GitHub link for now. Its not finalized but should get you started. :[GitHub - mpsaltis/dev\_EIP\_IOLData\_FB: This is a development project to read IOL data from a WAGO 765-4501 master connected to a 765-1703 DIO Hub.](https://github.com/mpsaltis/dev_EIP_IOLData_FB/tree/main) ---
### Author: ![MikePsaltis](https://sea2.discourse-cdn.com/flex016/user_avatar/www.wago.community/mikepsaltis/32/47_2.png) [@MikePsaltis](https://www.wago.community/u/MikePsaltis) #### Post date: [May 28, 2025, 2:53pm UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884/3 "2025-05-28T14:53:19Z")
I also forgot to mention that you can use the Web Based Management of the 765-4501 to do ISDU R/Ws. This was handy when testing. ---
### Author: ![Justin](https://avatars.discourse-cdn.com/v4/letter/j/3ab097/32.png) [@Justin](https://www.wago.community/u/Justin) #### Post date: [May 30, 2025, 6:29am UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884/4 "2025-05-30T06:29:35Z")
> [@MikePsaltis](#): > > 765-1703 Hi Mike, This is really useful. I didn’t respond immediately, as I have been focussed on putting together a broadly similar routine. Like you, I started with the EtherNetIP Services library and provide my current working here in case it might be of some use: ```auto FUNCTION_BLOCK FB_IOL_Index_Comms VAR_INPUT x_trigger : BOOL; x_execute : BOOL; port_number : BYTE; io_index : WORD; io_subindex : BYTE; io_length : WORD; read_flag : BOOL; t_timeout : TIME := T#500S; t_timegap : TIME := T#0MS; END_VAR VAR_OUTPUT x_status : EVAL_STATUS; s_state : STRING; s_iol_call_data : STRING(257); END_VAR VAR_IN_OUT data : ARRAY[0..255] OF BYTE; END_VAR VAR cip_class : ENIP.CIPClass := 16#83; //ISDU service of the IO-Field device cip_attribute : WORD := 0; //to avoid crash for unknown reason gs_done : BOOL; gs_busy : BOOL; gs_error : BOOL; state : INT; s_state_m1 : STRING; a_state : ARRAY[0..log_size] OF STRING; ii : INT; generic_service : ENIP.Generic_Service; usint_bytes : USINT_TO_BYTES; bytes_dint : BYTES_TO_DINT; cip_service : ENIP.CIPCommonService; cip_instance : DWORD; rec_data_size : UDINT; write_data : ARRAY[0..255] OF BYTE; o_timeout : TON; o_timegap : TON; flag_gap : BOOL; END_VAR VAR CONSTANT log_size : INT := 20; END_VAR IF x_trigger AND (o_timegap.Q OR x_status = EVAL_STATUS.rest) THEN //initialise flag_gap := FALSE; o_timegap(IN := flag_gap, PT := t_timegap); x_status := EVAL_STATUS.busy; generic_service( xDone => gs_done, xBusy => gs_busy, xError => gs_error, udiReceivedDataSize => rec_data_size, itfEtherNetIPDevice := IO_Link_Master, dwInstance := cip_instance, eClass := cip_class, wAttribute := cip_attribute ); CASE state OF //STATE OF MACHINE 0 : //initialisation state := 1; s_state := 'IOL-CALL - initialised'; 1 : //wait for execute IF x_execute THEN (* ERROR CHECKING *) IF port_number < 0 OR port_number > 8 THEN state := 999; s_state := 'IOL-CALL - port error'; ELSE cip_instance := port_number; state := 10; s_state := 'IOL-CALL - initialised'; END_IF ELSE s_state := 'IOL-CALL - waiting for execution command'; END_IF 10 : //IOL-CALL to read or write IF read_flag THEN state := 20; s_state := 'IOL-CALL - read selected'; ELSE state := 30; s_state := 'IOL-CALL - write selected'; END_IF 20 : //IOL-CALL to read cip_service := 75; //75 (0x4B) ISDU read service generic_service.eService := cip_service; generic_service.pReadData := ADR(data); //external buffer generic_service.udiReadDataSize := SIZEOF(data); //external buffer size //set indices write_data[0] := TO_BYTE(io_index); //index write_data[1] := TO_BYTE(SHR(io_index,8)); write_data[2] := io_subindex; //subindex generic_service.pWriteData := ADR(write_data); //internal buffer generic_service.udiWriteDataSize := 3; //internal buffer size generic_service.xExecute := TRUE; //start read state := 21; s_state := 'IOL-CALL - read start'; 21 : //wait for read response IF gs_busy AND o_timeout.Q THEN state := 999; s_state := 'IOL-CALL - read timeout'; ELSIF gs_error THEN state := 999; s_state := 'IOL-CALL - read error'; ELSIF gs_done THEN state := 40; s_state := 'IOL-CALL - read done'; END_IF 30 : //IOL-CALL to write cip_service := 76; //76 (0x4C) ISDU write service generic_service.pReadData := ADR(data); //external buffer generic_service.udiReadDataSize := SIZEOF(data); //external buffer size //set indices write_data[0] := TO_BYTE(io_index); //index write_data[1] := TO_BYTE(SHR(io_index,8)); write_data[2] := io_subindex; //subindex //append write data to internal buffer WagoSysPlainMem.MemCopySecure( pDest := ADR(write_data)+3, //copy to internal buffer udiDestSize := SIZEOF(write_data)-3, pSource := ADR(data), //copy source ist the external buffer udisourceSize := io_length, //length to copy bPadding :=0); generic_service.pWriteData := ADR(write_data); //internal buffer pointer generic_service.udiWriteDataSize := io_length + 3; //internal buffer size generic_service.xExecute := TRUE; //start write state := 31; s_state := 'IOL-CALL - write start'; 31 : //wait for write response IF gs_busy AND o_timeout.Q THEN state := 999; s_state := 'IOL-CALL - write timeout'; ELSIF gs_error THEN state := 999; s_state := 'IOL-CALL - write error'; ELSIF gs_done THEN state := 40; s_state := 'IOL-CALL - write done'; END_IF 40 : //copy data WagoSysPlainMem.MemCopySecure( pDest := ADR(s_iol_call_data), udiDestSize := SIZEOF(s_iol_call_data), pSource := ADR(data), udisourceSize := rec_data_size, bPadding :=0 ); state := 41; s_state := 'IOL-CAll - processed response'; 41 : //done Reset( m_status := EVAL_STATUS.done, m_state := 'IOL-CALL - done'); 999 : //error Reset( m_status := EVAL_STATUS.error, m_state := WagoAppString.Concat3('error = ','', TO_STRING(generic_service.eError))); ELSE Reset(m_status := EVAL_STATUS.busy, m_state := 'IOL-CALL - state not recognised'); END_CASE //state machine log IF s_state <> s_state_m1 THEN FOR ii := log_size TO 0 BY -1 DO IF ii > 0 THEN a_state[ii] := a_state[ii-1]; ELSE a_state[ii] := s_state; END_IF END_FOR END_IF s_state_m1 := s_state; //timeout TON o_timeout(IN := (x_status=EVAL_STATUS.busy), PT := t_timeout); ELSE IF x_status <> EVAL_STATUS.busy THEN // OTHERWISE ASSUME TIME GAP TO AVOID COMMS CONFLICT state := 0; x_status := EVAL_STATUS.rest; x_execute := FALSE; generic_service.xExecute := FALSE; END_IF END_IF flag_gap := TRUE; o_timegap(IN := flag_gap, PT := t_timegap); ///////////////////////////////////////////////////// METHOD PRIVATE reset (* METHOD TO RESET THE FB TO AN INITIALISED STATE *) VAR_INPUT m_status : EVAL_STATUS; m_state : STRING; END_VAR x_status := m_status; s_state := m_state; x_execute := FALSE; generic_service.xExecute := FALSE; state := 1; ``` ---
### Author: ![Justin](https://avatars.discourse-cdn.com/v4/letter/j/3ab097/32.png) [@Justin](https://www.wago.community/u/Justin) #### Post date: [May 31, 2025, 12:50pm UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884/5 "2025-05-31T12:50:19Z")
Hi again, Your example is brilliant - many thanks for sharing. I have worked it into my project, but have a quick follow-up question: how can I check if a port is active? Given documentation for 765-4501, I thought that I could access this information from the event log (Object 65, 0x41), attribute 2 (current state; 1=stopped, 2=empty, 3=present, 4=full/overwrite, 5=full/stop). The parameters that I set for this query are: ```auto EIP_read_data_size := 64; // Size of receive buffer. Can't leave this at 0, or no data will be read EIP_eService := 16#0E; // Get Attribute Single EIP_class := 16#41; // Object 65 (0x41) - IO-Link Event Log EIP_instance := port_number; // This is the physical port number (1-8) of the 765-450X IO-Link Master EIP_attribute := 2; // 2 returns current state of instance (1=stopped, 2=empty, 3=present, 4=full/overwrite, 5=full/stop) EIP_trigger := TRUE; // Setting this variable TRUE will execute the EIP function block ``` Unfortunately, this didn’t work as I had hoped. Grateful for any additional guidance. ---
### Author: ![MikePsaltis](https://sea2.discourse-cdn.com/flex016/user_avatar/www.wago.community/mikepsaltis/32/47_2.png) [@MikePsaltis](https://www.wago.community/u/MikePsaltis) #### Post date: [June 2, 2025, 3:01pm UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884/6 "2025-06-02T15:01:25Z")
Great, thanks for sharing your code here! You might be able to use the PQI data from the IO-Link master. This is part of the cyclic process image for the master. ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/8/8395ad134e88d8c7263c9ffcd9b81694b607f295.png) ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/3/34a466548106e8d26f63c7db734db8d7bc47a6d4.png) ---
### Author: ![Justin](https://avatars.discourse-cdn.com/v4/letter/j/3ab097/32.png) [@Justin](https://www.wago.community/u/Justin) #### Post date: [June 2, 2025, 3:56pm UTC](https://www.wago.community/t/codesys-communicatioins-with-io-link-master-765-45x/1884/7 "2025-06-02T15:56:29Z")
Yes, managed to work out integration with the PQI data today. Revised code that integrates this functionality providerd here: ```auto FUNCTION_BLOCK PUBLIC FB_IOL_Comms (* Authors : MWP, JV Last Edit : 30 May 2025 (JV) This FB manages communications with IO-Link devices via an IO-Link master *) VAR_INPUT port_number : DWORD := 1; // IO-Link master physical port number (e.g. 1-8) io_index : WORD := 19; // Index (default to product id) io_subindex : BYTE := 0; data_write : ARRAY[0..60] OF BYTE; // Data to write to IO-Link slave io_write_length : WORD; // Byte length of data to write to slave t_timeout : TIME := T#100S; END_VAR VAR_IN_OUT x_read_cmd : BOOL; x_write_cmd : BOOL; x_port_query : BOOL; END_VAR VAR_OUTPUT x_done : BOOL; x_busy : BOOL; x_error : BOOL; s_error : STRING; data_read : ARRAY[0..63] OF BYTE; io_read_length : UDINT; END_VAR VAR EIP : ENIP.Generic_Service; EIP_trigger : BOOL; EIP_done : BOOL; EIP_busy : BOOL; EIP_err : BOOL; EIP_class : ENIP.CIPClass; EIP_instance : DWORD; EIP_attribute : WORD; EIP_eService : ENIP.CIPCommonService; EIP_eError : ENIP.ERROR; EIP_write_data : ARRAY[0..63] OF BYTE; // Write buffer EIP_write_data_size : UDINT; EIP_read_data : ARRAY[0..63] OF BYTE; // Read buffer EIP_read_data_size : UDINT; EIP_rcvd_size : UDINT; x_read : BOOL; x_write : BOOL; x_query : BOOL; i_step : INT := 0; tonWatchDog : TON; (*======================================================== LIST OF RELATED VARIABLES DESCRIBED BY DEFINITION OF IO-LINK MASTER ======================================================== EIP_DI_status: DIGITAL INPUT STATUS Reference: WAGO I/O System Field documentation, Table 19 BYTES: 1 Each bit representing one port 0 = port is not a digital input; 1 = port is a digital input ======================================================== EIP_DI_data: DIGITAL INPUT DATA Reference: WAGO I/O System Field documentation, Tables 20 and 21 BYTES: 2 Not sure about use of these data ======================================================== EIP_x1_pqi: PORT QUALIFIER INFORMATION Reference: WAGO I/O System Field documentation, Table 37 of documentation BYTES: 1 Bit 0: reserved 1: reserved 2: reserved 3: event: 0 = port has no IO-Link event; 1 = port has IO-Link event 4: reserved 5: DevCom: 0 = no IO-Link device present; 1 = IO-Link device present 6: DevErr: 0 = no error/warning; 1 = error/warning 7: PQ: 0 = port qualfier data invalid; 1 = port qualifier data valid ======================================================== EIP_DO_status: DIGITAL OUTPUT STATUS Reference: WAGO I/O System Field documentation, Table 28 of documentation BYTES: 1 Each bit representing one port 0 = port is not a digital output; 1 = port is a digital output ======================================================== EIP_DO_data: DIGITAL OUTPUT DATA Reference: WAGO I/O System Field documentation, Table 28 of documentation BYTES: 2 Not sure about use of these data ======================================================== EIP_x1_enable_out: DIGITAL OUTPUT DATA Reference: WAGO I/O System Field documentation, Table 28 of documentation BYTES: 1 Bit 0: 0 = disable; 1 = enable Bit 1-7: reserved ========================================================*) END_VAR (* =======================================*) (* ===== [Set Function Block Busy] =====*) (* =======================================*) IF i_step > 0 THEN x_busy := TRUE; ELSE x_busy := FALSE; END_IF (* =============================*) (* ===== [State Machine] =====*) (* =============================*) CASE i_step OF 0 : // Idle IF x_read_cmd OR x_write_cmd OR x_port_query THEN i_step := 5; s_error := 'None'; END_IF 5 : // PLC will begin executing before the EIP connection is established. // Check for an EIP connection before trying to access to the IO-Link device. IF IO_Link_Master.eState <> IoDrvEthernetIp.AdapterState.RUNNING THEN i_step := 999; x_error := TRUE; s_error := 'EIP Master Not Running'; ELSIF NOT FN_Port_Active(port_number) THEN i_step := 999; x_error := TRUE; s_error := 'EIP Port not active'; ELSIF port_number > GVL.max_iol_ports THEN i_step := 999; x_error := TRUE; s_error := 'Requested IOL port number exceeds project maximum'; ELSE i_step := 10; END_IF 10 : // determine if read or write call IF x_write_cmd THEN i_step := 100; // Steps 100 to 199 write to device ELSIF x_read_cmd THEN i_step := 200; // Steps 200 to 299 read from device ELSIF x_port_query THEN i_step := 300; // Steps 300 to 399 read from device END_IF (* ===== [Write to device] =====*) 100 : // initialise write x_write := TRUE; i_step := 110; 110 : // check if complete IF NOT x_write AND EIP_done THEN x_done := TRUE; i_step := 999; END_IF (* ===== [Read from device] =====*) 200 : // initialise read x_read := TRUE; i_step := 210; 210 : // check if complete IF NOT x_read AND EIP_done THEN x_done := TRUE; data_read := EIP_read_data; io_read_length := EIP_read_data_size; i_step := 999; END_IF (* ===== [Port query] =====*) 300 : // initialise query //x_query := TRUE; //i_step := 310; i_step := 999; x_error := TRUE; s_error := 'Port query not currently working'; 310 : // check if complete IF NOT x_query AND EIP_done THEN x_done := TRUE; data_read := EIP_read_data; io_read_length := EIP_read_data_size; i_step := 999; END_IF (* ===== [Step 999 resets the fuction block] =====*) 999 : // Reset x_done := FALSE; x_error := FALSE; s_error := ''; x_busy := FALSE; x_read_cmd := FALSE; x_read := FALSE; x_write_cmd := FALSE; x_write := FALSE; EIP_trigger := FALSE; i_step := 0; END_CASE (* ============================================*) (* ===== [Process EIP service requests] =====*) (* ============================================*) // if x_query TRUE, then initialise query of the service IF x_query THEN EIP_read_data_size := 64; // Size of receive buffer. Can't leave this at 0, or no data will be read EIP_eService := 16#0E; // Get Attribute Single EIP_class := 16#41; // Object 65 (0x41) - IO-Link Event Log EIP_instance := port_number; // This is the physical port number (1-8) of the 765-450X IO-Link Master EIP_attribute := 2; // 2 returns current state of instance (1=stopped, 2=empty, 3=present, 4=full/overwrite, 5=full/stop) EIP_trigger := TRUE; // Setting this variable TRUE will execute the EIP function block x_query := FALSE; END_IF // if x_read TRUE, then initialise read parameters and execute the read service IF x_read THEN EIP_write_data[0] := TO_BYTE(io_index); // Index (LSB) EIP_write_data[1] := TO_BYTE(SHR(io_index,8)); // Index (MSB) EIP_write_data[2] := io_subindex; // Subindex EIP_write_data_size := 3; // 3 bytes for index/subindex EIP_read_data_size := 64; // Size of receive buffer. Can't leave this at 0, or no data will be read EIP_eService := 16#4B; // Read is 0x4B, Write is 0x4C EIP_class := 16#83; // Object 131 (0x83) - IO-Link Device Parameters EIP_instance := port_number; // This is the physical port number (1-8) of the 765-450X IO-Link Master EIP_attribute := 0; // Always 0 EIP_trigger := TRUE; // Setting this variable TRUE will execute the EIP function block x_read := FALSE; END_IF // if x_write TRUE, then initialise write parameters and execute the write service IF x_write THEN EIP_write_data[0] := TO_BYTE(io_index); // Index (LSB) EIP_write_data[1] := TO_BYTE(SHR(io_index,8)); // Index (MSB) EIP_write_data[2] := io_subindex; // Subindex WagoSysPlainMem.MemCopySecure( // copy write data to internal buffer pDest := ADR(EIP_write_data)+3, udiDestSize := SIZEOF(EIP_write_data)-3, pSource := ADR(data_write), udisourceSize := io_write_length, bPadding :=0 ); EIP_write_data_size := 3 + io_write_length; // 3 bytes for index/subindex, plus byte length of data to write EIP_read_data_size := 0; // Can be set to 0 for write service EIP_eService := 16#4C; // Read is 0x4B, Write is 0x4C EIP_class := 16#83; // Object 131 (0x83) - IO-Link Device Parameters EIP_instance := port_number; // This is the physical port number (1-8) of the 765-450X IO-Link Master EIP_attribute := 0; // Always 0 EIP_trigger := TRUE; // Setting this variable TRUE will execute the EIP function block x_write := FALSE; END_IF // Instance of ENIP.Generic_Service function block // This function block performs a generic service at an EtherNet/IP Adapter // The message will be sent as an unconnected explicit message request EIP( xExecute := EIP_trigger, xDone => EIP_done, xBusy => EIP_busy, xError => EIP_err, itfEtherNetIPDevice := IO_Link_Master, eClass := EIP_class, dwInstance := EIP_instance, wAttribute := EIP_attribute, eError => EIP_eError, eService := EIP_eService, pWriteData := ADR(EIP_write_data), udiWriteDataSize := EIP_write_data_size, pReadData := ADR(EIP_read_data), udiReadDataSize := EIP_read_data_size, udiReceivedDataSize => EIP_rcvd_size ); (* =============================================*) (* ===== [Process EIP service responses] =====*) (* =============================================*) IF EIP_done THEN EIP_trigger := FALSE; END_IF IF EIP_err THEN x_error := TRUE; s_error := WagoAppString.Concat3('EIP error = ','', TO_STRING(EIP_eError)); i_step := 999; END_IF (* ==============================*) (* ===== [Watchdog Timer] =====*) (* ==============================*) tonWatchDog( IN := i_step <> 0, PT := t_timeout); IF tonWatchdog.Q THEN x_error := TRUE; s_error := 'Timeout'; i_step := 999; END_IF (* ==============================*) (* ===== [FN_Port_active] =====*) (* ==============================*) FUNCTION FN_Port_Active : BOOL VAR_INPUT port_number : DWORD := 1; END_VAR VAR byte_value : BYTE; byte_bit : BYTE_AS_BIT; END_VAR byte_value := FN_Port_PQI(port_number); byte_bit(B:=byte_value, B5=>FN_Port_Active); (* ===========================*) (* ===== [FN_Port_PQI] =====*) (* ===========================*) FUNCTION FN_Port_PQI : Byte VAR_INPUT port_number : DWORD := 1; END_VAR VAR END_VAR IF port_number = 1 THEN FN_Port_PQI := EIP_x1_pqi; ELSIF port_number = 2 THEN FN_Port_PQI := EIP_x2_pqi; ELSIF port_number = 3 THEN FN_Port_PQI := EIP_x3_pqi; ELSIF port_number = 4 THEN FN_Port_PQI := EIP_x4_pqi; ELSIF port_number = 5 THEN FN_Port_PQI := EIP_x5_pqi; ELSIF port_number = 6 THEN FN_Port_PQI := EIP_x6_pqi; ELSIF port_number = 7 THEN FN_Port_PQI := EIP_x7_pqi; ELSIF port_number = 8 THEN FN_Port_PQI := EIP_x8_pqi; END_IF ```