Hollysys Communication Failure Analysis
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The fault occurrence process and phenomena are all: First, a certain module on the 10th station of the system had an uninterrupted offline alarm. After the alarm was eliminated, it became normal. After this alarm occurred and lasted for a period of time, other modules on station 10 began to have frequent offline alarms. Appears immediately after clearing the alarm. The module serial numbers that caused alarms in n faults in 2008 were all modules after module 12# on station 10#, which meant that all parameters of modules after module 12# on station 10# could not be collected and displayed. All the fault phenomena within the control include the flashing of the COM light on the module, indicating a communication failure with the main control unit.
It is recommended to replace module 12 of station 10 and its base. A failure of a contact in DP communication may cause the failure of the entire DP link.
Use wires to short-circuit (11# module 37, 13# module 37) (11# module 38, 13# module 38). If the latter is normal, you can definitely judge that there is something wrong with the 12# module base. In fact, the base does not have a chip or anything like that, it only serves to connect the terminals to the module.
Upstairs, have you done this? If module 12 is short-circuited without removing it, it will also cause communication errors~! I personally don’t know if it’s right or not·
That's how we use it. In fact, all modules 37 and 38 are connected. Just like 37 and 38 are the main DP lines, all DP modules are connected to 37 and 38. Modbus is also the same way. But if the bad module is next to the terminal resistor, there will be no way.
I know that 37.38 is connected. What I am concerned about is that you directly connected No. 11 to 13 to 37.38 of the module during online operation, and then disconnected the base of No. 12 module, so that the module will not go offline, but I am worried about whether it will affect the DP communication~~ Or, disconnect the base of No. 12 module and then connect 11 and 13? ? ? ? ? (In this way, all the modules after the 12th will be offline) Because this involves the issue of whether it affects online operation, so please tell me~~ We also replaced the module base ~ FM161 once. We changed it while the car was parked. Disconnect the base, remove it, replace it with a new one, wire it, connect it to the power supply, and fix it~ It was done in this way. I have never tried to change it online~~~ So I want to know if the one upstairs is changed online? Specific steps and impact on system communication~!
Next time you park your car, try it online and you will know what I said is right.
It is recommended to replace the No. 12 module, which may be affected by the No. 12 module! And it stands to reason that any module on the DP bus going offline should not affect other modules.
When using 37 and 38, be careful not to use a T-shaped connection. Long-term T-connections are not good. one. Since the poster said that module No. 12 started to fail, module No. 12 is usually the second module in the second column on the front, so it is basically ruled out that the DP line from the B master to the second column is oxidized or has poor contact. two. I don’t know whether the station has a DP repeater, whether the DP repeater is from Siemens or FM1201. If there is a DP repeater, whether the module behind the DP repeater is also offline. three. Everyone generally thinks that there is something wrong with module No. 12. In fact, it can only be said that module No. 12 is more likely to be suspected. The only solution is to analyze the equipment alarm records, determine the offline range of the module, perform unplugging and plugging, and perform repeated troubleshooting. It is unlikely that the problem is caused by a bad base. You can also pry the base up and down twice to make it more tightly integrated. Four. It's really frustrating to encounter such a problem, and if you don't go offline very often, it will be very difficult to solve.
I also encountered a similar problem, and now I have replaced it with a Siemens DP cable, and the effect is good. What you're talking about is probably a problem with the bottom plate, or dust causing a terminal resistance effect, which will cause problems in the future. Faner's method is correct. It is equivalent to connecting all modules to the bus. No matter how they are connected, it will be OK. This is my understanding.
What you said is right. I agree and understand it~ But what I asked was your specific replacement steps~··I’m not asking you whether this is useful, right·~ Read my reply carefully~~ Because the steps are different, the results are different~ So the point of my question is to connect No. 12 directly without dismantling it? This post was last edited by afei6896 on 2009-3-24 18:04 ]
Back to A Fei 6896: The cause of offline may be that the base plate is broken, or the contact is poor, etc. The way to judge the quality of the base plate is the method I mentioned above. It doesn't matter whether you pull out the module or not. Pulling out the module can only make the module offline (pay attention to whether the points of the module are interlocked when pulling it out). To determine whether there is a problem with the module, try replacing it with a good module, or changing its position with another module. It turned out that I also encountered a series of large-area modules going offline. No matter how much I checked the modules, I couldn't find out the cause. Later I found that the air conditioner was broken. After I repaired the air conditioner and turned it on, everything was fine. I remember that the indoor temperature was about 35 degrees when the air conditioner was not turned on, and about 23 degrees when the air conditioner was turned on. The system has been running at about 23 degrees for 6 years. This post was last edited by faner on 2009-3-25 09:43 ]