Unable to write STRUCT value #7
Comments
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The only struct related data type that the driver handles for now is strings, see comments on STRUCT_STRING in src/etherip/types/CIPData.java. |
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Allen Bradley message type says I/O Message as the Tag Type. Is there any way to write on this tag type? |
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No idea. I've developed the driver based on the generic EtherNet/IP specification available from http://www.odva.org which describes the basic CIP commands, and Allen Bradley document 1756-RM005A-EN-E.pdf, "Logix5000 Data Access", which describes the CIP service codes specific to the ControlLogix 5000 series for reading and writing tags. In those documents I found no detail on structures. 1756-RM005A-EN-E.pdf only mentions that they exist. It was pure luck that the string read/write worked out. |
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Hi Kasemir, I was able to get the details on this tag type from PLC, when I read the value the CIPData type is STRUCT. But I am not ablle to write using that. Tag name is S1_ScreenId, please let me know how to write values to this tag.
READ OutPut |
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Again, no idea about the STRUCT, you'll have to figure that out on your own. What might be easier, though, is reading/writing "S1_ScreenID.DATA" as an SINT array. |
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Hi, tried as per your suggestion above, NPE in decode. CIPData value1 = plc.readTag("S1_ScreenId.DATA[0]",1); java.lang.NullPointerException |
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java.lang.NullPointerException at etherip.protocol.CIPReadDataProtocol.decode(CIPReadDataProtocol.java:56): CIPReadDataProtocol has no code in line 56 that could throw an NPE, https://github.com/EPICSTools/etherip/blob/master/src/etherip/protocol/CIPReadDataProtocol.java Look, I really can't help you with that. |
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Hey kasemir, I figured out the request error and corrected it. Now i am getting the below error, do you know why PLC would send this? Jun 27, 2016 11:03:49 AM etherip.protocol.Connection write Jun 27, 2016 11:03:49 AM etherip.protocol.Connection read java.lang.Exception: Expected CIP_WriteData_Reply (0xCD), got CM_Unconnected_Send_Reply (0xD2) |
If you found an error in the code or have a suggested addition, please consider a pull request.
I would hope that when you dump the complete protocol at a higher log level there's been an error code in there that helps to understand why the PLC didn't send a WriteDataReply to a WriteDataRequest. |
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@uthaman This driver was not created for handling UDT structures. It could certainly be modified to do so using Logix5000 Data Access which outlines how to use the GetInstance Attribute List Service (0x55) and the Read Template Service (0x4c) to get a list of tags and the definitions for UDTs in the processor. There are many examples on then accessing the data in these UDTs. |
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Not sure about writing, but for reading, #11 fixed the tag parsing, so "some_struct.element" as a tag name should now allow accessing an element of a structure, and as long as that element is a plain REAL, DINT, ... it should read and maybe also write it. |
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Hi, Today, anybody has already comunication with Omron PLC using Java Ethernet/IP ? |
Just wanted to add this for future user reference. The easiest thing to do here is, count the length of the string you want to write. Your screenshot appears to be 8, so then convert characters to ascii code, and foorloop to write one at a time. If the datatype is String then you can read without doing all this, but if is a custom string UDT you might need to read as below. Example below: Read example: String stringID_LenTag = "S1_ScreenID.LEN"; // Tag for length
CIPData tagData= plc.readTag(stringID_LenTag);
int tagDataIDLength = tagData.getNumber(0).intValue(); // string length
StringBuilder stringSb = new StringBuilder();
for(int i = 0; i < tagDataIDLength; i++)
{
CIPData tempData = plc.readTag(String.format("S1_ScreenID.DATA[%d]", i));
stringSb.append(Character.toString ((char) tempData.getNumber(0).intValue()));
}Write example: // convert your string to ascii somewhere here
int[] stringAsciiValues = new int[]{ 72,101,108,108,111 };
// Set length of string in case is shorter or longer
stringID_LenData.set(0, stringAsciiValues.length);
plc.writeTag(stringID_LenTag, stringID_LenData);
for(int i = 0; i < stringAsciiValues.length; i++)
{
CIPData tempData = plc.readTag(String.format("S1_ScreenID.DATA[%d]", i));
tempData.set(0, stringAsciiValues[i]);
plc.writeTag(String.format("S1_ScreenID.DATA[%d]", i), tempData);
} Note that my tag name is different. Hope this helps someone in the future. : ) |
Hi,
I am not able to write Message type data to PLC, When i read the value and check the Type , it says "STRUCT" and when I use the same to write it says "(CIP type does not match object type)"
final byte[] data = new byte[] { (byte)0xCE, (byte)0x0F, 7, 0, 0, 0, 'w', 'j', 'h', ' ', '1', '2', '4' };
CIPData value1 = new CIPData(Type.STRUCT, data);
plc.writeTag("S1_ScreenId", value1);
Below is the finest logs.
Jun 21, 2016 4:32:07 PM etherip.protocol.Connection write
FINER: Protocol Encoding
Encapsulation Header
UINT command : SendRRData (0x006F)
UINT length : 64
UDINT session : 0x1002D600
UDINT status : 0x00000000
USINT context[8] : 'Funstuff'
UDINT options : 0x00000000
Send RR Data
UDINT interface handle : 0
UINT timeout : 0
UINT count (addr., data): 2
UINT address type : 0x0 (UCMM)
UINT address length : 0x00
UINT data type : 0xB2 (Unconnected Message)
UINT data length : 48
MR Request
USINT service : CM_Unconnected_Send (0x52)
USINT path : Path (2 el) Class(0x20) 0x6 (ConnectionManager), instance(0x24) 1
CM_Unconnected_Send
USINT tick_time : 10
USINT ticks : -16
UINT message size : 33
/// embedded message /// (33 bytes)
MR Request
USINT service : CIP_WriteData (0x4D)
USINT path : Path Symbol(0x91) 'S1_ScreenId', 0x00
USINT type, data : 'wjh 124'
///\ embedded message ///
USINT pad : 0 (odd length message)
USINT path size : 1 words
USINT reserved : 0
USINT port 1, slot 0
Jun 21, 2016 4:32:07 PM etherip.protocol.Connection write
FINEST: Data sent (88 bytes):
0000 - 6F 00 40 00 00 D6 02 10 00 00 00 00 46 75 6E 73 - [email protected]
0010 - 74 75 66 66 00 00 00 00 00 00 00 00 00 00 02 00 - tuff............
0020 - 00 00 00 00 B2 00 30 00 52 02 20 06 24 01 0A F0 - ......0.R. .$...
0030 - 21 00 4D 07 91 0B 53 31 5F 53 63 72 65 65 6E 49 - !.M...S1_ScreenI
0040 - 64 00 A0 02 01 00 CE 0F 07 00 00 00 77 6A 68 20 - d...........wjh
0050 - 31 32 34 00 01 00 01 00 - 124.....
Jun 21, 2016 4:32:07 PM etherip.protocol.Connection read
FINEST: Data read (46 bytes):
0000 - 6F 00 16 00 00 D6 02 10 00 00 00 00 46 75 6E 73 - o...........Funs
0010 - 74 75 66 66 00 00 00 00 00 00 00 00 00 00 02 00 - tuff............
0020 - 00 00 00 00 B2 00 06 00 CD 00 FF 01 07 21 - .............!
Jun 21, 2016 4:32:07 PM etherip.protocol.Connection read
FINER: Protocol Decoding
Encapsulation Header
UINT command : SendRRData (0x006F)
UINT length : 22
UDINT session : 0x1002D600
UDINT status : 0x00000000 (OK)
USINT context[8] : 'Funstuff'
UDINT options : 0x00000000
Received RR Data
UDINT interface handle : 0
UINT timeout : 0
UINT count (addr., data): 2
UINT address type : 0x0 (UCMM)
UINT address length : 0
UINT data type : 0xB2 (Unconnected Message)
UINT data length : 6
MR Response
USINT service : CIP_WriteData_Reply (0xCD)
USINT reserved : 0x0
USINT status : 0xffffffff ()
USINT ext. stat. size : 0x1
USINT ext status : 0x2107 (CIP type does not match object type)
Jun 21, 2016 4:32:07 PM etherip.protocol.Connection write
FINER: Protocol Encoding
Encapsulation Header
UINT command : UnRegisterSession (0x0066)
UINT length : 0
UDINT session : 0x1002D600
UDINT status : 0x00000000
USINT context[8] : 'Funstuff'
UDINT options : 0x00000000
Jun 21, 2016 4:32:07 PM etherip.protocol.Connection write
FINEST: Data sent (24 bytes):
0000 - 66 00 00 00 00 D6 02 10 00 00 00 00 46 75 6E 73 - f...........Funs
0010 - 74 75 66 66 00 00 00 00 - tuff....
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