Activity for Nilay Das
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Nilay Das posted a comment on discussion Help
Hi, I see that in BACnet IP "Max APDU Length Accepted" is 1476. However, if we calculate backwards from what is standard Ethernet frame size it mismatches. 1518 = Max MTU i.e. Ethernet frame size. 42 = Ethernet Header + IP header + UDP header 4 = BVLC 2 = NPDU unicast Note: I didnt add the preamble (7 bytes) and delimiter (1 byte) of ethernet frame in the above calculation. If we calculate 1518 - 42 - 4 - 2 = 1470. Which is lesser than APDU size 1476. In such case if we pack a full frame APDU, wont...
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Hi, I am seeing a functionality in the stack where, I specified the CoV increment = 2 and subscribe an object. I am changing the value making sure the "delta" / change remain below CoV increment. However, I see that after certain time Yabe suddenly received latest present value. When I look at the MSTP captured log I found that there is an unconfirmedCoVnotification sent from the device to Yabe with current present value. I repeated the test many times and result is consistent. for e.g. a temperature...
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Hi, I am seeing a functionality in the stack where, I specified the CoV increment = 2 and subscribe an object. I am changing the value making sure the "delta" / change remain below CoV increment. However, I see that after certain time Yabe suddenly received latest present value. When I look at the MSTP captured log I found that there is an unconfirmedCoVnotification sent from the device to Yabe with current present value. I repeated the test many times and result is consistent. for e.g. a temperature...
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Hi, I am seeing a functionality in the stack where, I specified the CoV increment = 2 and subscribe an object. I am changing the value making sure the "delta" / change remain below CoV increment. However, I see that after certain time Yabe suddenly received latest present value. When I look at the MSTP captured log I found that there is an unconfirmedCoVnotification sent from the device to Yabe with current present value. I repeated the test many times and result is consistent. for e.g. a temperature...
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Hi, I am seeing a functionality in the stack where, I specified the CoV increment = 2 and subscribe an object. I am changing the value making sure the "delta" / change remain below CoV increment. However, I see that after certain time Yabe suddenly received latest present value. When I look at the MSTP captured log I found that there is an unconfirmedCoVnotification sent from the device to Yabe with current present value. I repeated the test many times and result is consistent. for e.g. a temperature...
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Thank you Steve, We can close this discussion with conclusion that the the bug is with Wireshark version w are using. Just now tested with Wireshark Version 2.6.20. There is no malformed packet now for UnconfirmedCOVNotification. It is now confirmed that the issue is with Wireshark version we are using. Wireshark Version 3.4.3 (v3.4.3-0-g6ae6cd335aa9) Wireshark Version 3.0.6 (v3.0.6-0-g908c8e357d0f) Note - bug in v2.6.20: With Wireshark Version 2.6.20, Simple-ACK to subscribeCOV will show Ethernet...
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Thank you Steve, We can close this discussion with conclusion that the the bug is with Wireshark version w are using. Just now tested with Wireshark Version 2.6.20. There is no malformed packet now for UnconfirmedCOVNotification. It is now confirmed that the issue is with Wireshark version we are using. Wireshark Version 3.4.3 (v3.4.3-0-g6ae6cd335aa9) Wireshark Version 3.0.6 (v3.0.6-0-g908c8e357d0f) Note - bug in v2.6.20: With Wireshark Version 2.6.20, Simple-ACK to subscribeCOV will show Ethernet...
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Thank you Steve, We can close this discussion with conclusion that the the bug is with Wireshark version w are using. Just now tested with Wireshark Version 2.6.20. There is no malformed packet now for UnconfirmedCOVNotification. It is now confirmed that the issue is with Wireshark version we are using. Wireshark Version 3.4.3 (v3.4.3-0-g6ae6cd335aa9) Wireshark Version 3.0.6 (v3.0.6-0-g908c8e357d0f) Note - bug in v2.6.20: With Wireshark Version 2.6.20, Simple-ACK to subscribeCOV will show Ethernet...
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Hi Steve, Thank you for the information. I am using Wireshark Version 3.0.6 (v3.0.6-0-g908c8e357d0f) . BACnet Stack version 0.8.6. I am planning to do the following and get back to you with my findings: Download any try Wireshark Version 2.6.20 update all the cov related files in my code to bacnet stack v1.0.0. And will try again. Regards, Nilay
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HI Steve, Thank you for providing the details. I tried the code as suggested by you. However, Wireshark still showing it as malformed for both MSTP and IP. For your reference, I am attaching the screenshot along with hex dump of complete MSTP packet. When I compare my packet(below) with yours(above) , it looks fine. Let me know if there is anything wrong in the packet I am missing or its the wireshark bug? Character string data used = 35 32 31 2c MSTP 0000 55 ff 06 00 02 00 26 3b 01 00 10 02 09 03...
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Hi, I added SubscribeCOV service for CSV objects. However, when I see the Wireshark log of unconfirmedCOVNotification, it always saying malformed packet. For me the same for AI object working fine. I compared CSV with AI object unconfirmedCOVNotification packet, but could not identify any issue. Need your suggestion and help on what exactly going wrong here. AI object Value = 1 81 0a 00 25 01 00 10 02 09 12 1c 02 00 00 02 2c 04 c0 01 36 39 78 4e 09 55 2e 21 01 2f 09 6f 2e 82 04 00 2f 4f CSV object...
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Hi, I added SubscribeCOV service for CSV objects. However, when I see the Wireshark log of unconfirmedCOVNotification, it always saying malformed packet. For me the same for AI object working fine. I compared CSV with AI object unconfirmedCOVNotification packet, but could not identify any issue. Need your suggestion and help on what exactly going wrong here. AI object Value = 1 81 0a 00 25 01 00 10 02 09 12 1c 02 00 00 02 2c 04 c0 01 36 39 78 4e 09 55 2e 21 01 2f 09 6f 2e 82 04 00 2f 4f CSV object...
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Thank you Steve, for providing the clarity I was desperatly looking for. Nilay
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Hi, Can any one please provide clarity on this. Are all BIP device is to support BBMD functionality. If a Device need to have BBMD, is it that a. Both BBMD and BIP functionality will be working at the same time. b. Or, device is to provide BBMD and BIP as an option to select for i.e. can act like either BBMD or BIP at any given time but not both at the same time. My understanding is either a BACnet device can act as BBMD or BIP at any given time. A device can have both BBMD and BIP as functional...
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Hi, My understanding is either a device can act as BBMD or BIP at any given time. A device can have both BBMD and BIP as funtional option to select. But a device can not act as BBMD and BIP at the same time. Please provide clarity. When I look at ASHARE docuemnt I see that BBMD is to be a seperate device type. ------ "Application to all BACnet device types (devices, routers, BBMDs)" However, when I see epic of bacnet application specific controller, I see that for BACnet IP it check mark BBMD option...
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Hi, Thank you for your information. I realised that I was using Yabe 1.1.9.0 version. After I upgraded to latest 1.2.00 it started working. Nilay
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Hi, I am working on MSTP. What I found is that, when object list is too large that it cross permissible APDU lengnth 480. BACnet stack returns segment error. And after that tool(yabe) is not proceeding to query all objects using "property array index". My understanding is, when the tool(YABE) is querying read property objevt list and get "segment not supported" error response, it will start enquering Object List using "array index". Wehere array index 0 will be responded with "total number of supported...
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Hi, I am working on MSTP. What I found is that when object list is too large that it cross permissible APDU lengnth 480. BACnet stack returns segment error. And it is not proceeding to query all objects using "property array index". My understanding is, when the tool(YABE) is querying read property objevt list and get "segment not supported" error response, it will start enquering Object List using "array index". Wehere array index 0 will be responded with "total number of supported object". Subsequently...
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Hi, Is all device on bacnet/ip is by default to be BBMD capable / enabled? In code I see that when I enabled BACnet/IP (BACDL_BIP), BBMD macro (BBMD_ENABLED) too get enabled by default, however in the standard it is mentioned as seperate device type - "Application to all BACnet device types (devices, routers, BBMDs)" Please provide clarity. Nilay
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