when I read 802.3bp-2016 protocol, i met a term "UCT" which I can't find its definition. For example, in Fig 97-13 RFER monitor state diagram, there is a UCT flow from INIT_CNT to WAIT state. Can anybody help me to understand this definition?
unconditional transition
IEEE 802.3 SECTION 1, 1.2.1 State diagram conventions
The label UCT designates an unconditional transition.
Related
I am working on making a custom controller for an aquarium light. I was able to figure out how to adjust the light's internal clock, and I was able to capture some of the communication, and I found this timecode 545f0d31574d52565951607631 which translated to ascii from hex becomes T_ 1WMRVYQ`v1. I know for sure it's the timecode, because it works as expected.
Anyone know what it is? Is it BLE specific? anyone know how to alter it?
I'm pretty sure the first 4 numbers are not part of the code, but a indicator for the device.
Edit:
It is BLE. I should have been more clear. It does most of the transmission on UUID 1000, with the characteristic uuid being 1001. The device doesn't have a built-in clock that I can see. It turn's on and off at the times I specify in the developer’s app. After a power failure, it "resets" to midnight. I know that value is the timecode, because when I input it using gatter tools, I can see the light reacts accordingly. I added a photo of it updating. –
You hint that that this is a Bluetooth Low Energy (BLE) device.
If it is BLE, then the UUID of the characteristic might be in the 16-bit UUID Numbers document. If it is a custom characteristic, then it will not. Official characteristics have the base address of 0000xxxx-0000-1000-8000-00805F9B34FB and only the four missing values are documented.
The specification for how time can be shared over BLE is documented in the GATT Specification Supplement if it is a Bluetooth SIG adopted characteristic.
It might be helpful if you update the question with what this values gives as the value on the light's internal clock.
I am rather new to uC programming and have hit a wall trying to find the base register address of comparator peripherals for the stm32f303k8. I couldn't find the info in either the reference manual, datasheet, or programming manual, as well as many other hits on various searches.
I've seen that if a clock is enabled for the comparators it runs on the AHB clock, but a separate diagram shows the AHB feeding into both APB1 and APB2 and the comparators were specifically placed under the APB2. I am quite confused and would welcome any help (short of using libraries!), even a search string pointing me in the right direction.
You find the answer in the
reference manual
of your STM32F303k8 rather than in its
datasheet.
In section 3.2.2 of the reference manual, you find both the relation between the peripherals and the buses through which you can reach them, and the boundary/base addresses of the peripheral registers.
On Table 4 on pages 57/58 is for your controller subfamily.
Here, I find a line on SYSCFG + COMP + OPAMP, which may be what you are looking for. Base address for all is 0x4001 0000, connection is through APB2.
Edit:
If you want to check the documentation which buses/clocks are needed along the way to drive the peripheral, I recommend starting at Fig. 1 in Ch. 2 (p. 13) of the datasheet. Here, you find that APB2 is driven through AHB2, and that COMPs are configured through SYSCFG CTL. The clock tree depicted in Fig. 2 in Sec. 3.6 (p. 19) shows that APB2 clock is driven (with another prescaler) by the AHB clock (HCLK). The details are described in Ch. 2 of the reference manual.
I personally prefer to start with the clock tree editor tool embedded to STM32CubeMX because I feel too lazy to look up all the information at the beginning of development. This gives one the chance to start from a reasonable guess and verify if the clock settings are the needed ones afterwards.
I've read and heard several times that, reachability graph is a particular type of Transition System, with one initial and UNDEFINED number of final markings.
But if you construct the reachability graph, you have very clear cases of final markings. Does this mean that you can't know which will be your final marking depending on how you fire the transitions?
Because, it's obvious that you can enumerate/count the number of final markings.
The number of reachable markings in a given reachability graph is possibly undefined. It is undefined in the case of a graph which has an infinite number of reachable markings.
I think you misinterpreted the meaning of "undefined" in this context. To define a reachability graph, you need to specify the states and transitions (a transition system), and you need to specify the initial state. Nothing more, the definition is already complete. The set or number of final states follows from this definition, but it isn't part of the definition, hence "undefined". It would be redundant to include it in the definition.
Compare this with finite automata used as acceptors. There, you must define which states are accepting (=final). Without this information, the definition would be incomplete.
I am implementing HMM(Hidden markov model).I have obtained a dataset of TCP flags such as Synchronized, Reset, Acknowledgement, FIN/ACK, PUSH/ACK.
The problem is I have to find the number of states so that I can calculate the conditional probabilities, transition probabilities, emission probabilities.
I have assumed random number of states considering the TCP flags as observables. Using Baum-Welch algorithm calculated the transition as well as emission probabilities. But taking random number of states we do not know whether the output is accurate.
So we are trying to find a better way to find out number of states and specifically which are the states to be used.
We are trying to implement the following paper Adaptive IDS using hybrid approach.
Any help would be appreciated.
Thanks in advance!
Thinks are easier or I do not understand the question.
SYN, SYN/ACK, ... are TCP flags. Interpret them as a first classification of TCP messages, so, as TCP message types. These are the events in the TCP finite-state machine.
The states of TCP finite state machine are CLOSE_WAIT, FIN_WAIT_1, ... . In total, 12 states.
If you look for "tcp state machine" in google images, you will easily find a draw of the state machine. By example: http://www.ssfnet.org/Exchange/tcp/Graphics/tcpStateDiagram1.gif
Synchronized is not a TCP flag nor state.
I'd like to learn more about Timed Automata to verify real-time systems. Currently, I'm trying to get myself familiar with a tool called UPPAAL.
I drew some simple graphs and added different properties. The entire model is supposed to represent a production cell system where different mechanical units pass a block to each other.
I've modelled the block (BlockCycle), 2 mechanical units (Feeder, FeederBelt) and 2 sensors which sense the arrival of the block.
Even though I thought my system would make sense, it gets deadlocked:
The target states of this transition violate the invariants. This is not a problem, as long as you intended your model to behave like this.
(No I didn't. ;P)
I can't seem to find the reason for the deadlock, though. The tool points me to the BlockCycle model but I didn't specify any invariant there. In fact, all the transition requirements are fulfilled so the transition (from Pos7 to Pos8) should definitely be taken.
Below you'll see how the systems evolves and finally gets stuck (error message pops up).
Labels:
green : property check (e.g. FB_Running means FB_Running == true )
dark blue: property updates/assignments
dark red: locations (e.g. Pos7 or Pos8)
The BlockCycle model with the respective transition in question:
My Question: Why does the system deadlock even though there are still transaction which could be taken.
Edit1: When I remove the invariant property of Sensor7's location Active (called BlockAtPos[7]) the deadlock is resolved. So I guess, since there is no synchronization between Sensor7 and BlockCycle for the last transition before it deadlocks, that would cause to a contradiction (BlockAtPos[7] becoming false while the sensor has not yet the chance to take the InActive transition) and thus violating the invariant.
Note: You can find my UPPAAL code/file here: pcs.xml.