Sanif

Problem solved!!! The culprit is the 1747-AIC module on the first SLC on the network (node 01). We swapped it for a new one and problem is gone. The problem with intermittent connection is that is is very difficult to pinpoint the fault. With the benefit of a brand new AIC module, we are able to isolate the SLC one by one and finally locate the fault. Thanks every one for you kind assistance. ps.s slcman. My configuration set up was exactly the same as yours. Cheers!

I tried the Hofix, but problem still persist. I am beginning to think that it has to do with the token passing on DH-485. Can this be a possibility?

Thanks for all the replies. I am using RSLinx Classic v 2.50. Based on the Hotfix from TechJunkie, I gather the fault is more on RSLinx rather than the hardwire connection in the network. Should I be concern at all if it is only on the RSLinx? The SLCs are running happily as far as I can tell, but this problem with the network dropping out of RSLinx has rattled some people. I will implement the Hotfix as suggested by Techjunkie and keep everyone posted. Thanks.

Hello, I need some help with a DH-485 network. I have four (4) SLC 5/03 connected on a single DH-485 network. This network is then connected to a DH+ network via a 1785-KA5 bridge. All SLC have the 1747-AIC module and I confirmed there are correctly wired and terminated at the ends. AIC module confirmed to be in working order, as I was able to go online to all SLCs via its AIC module. However in RSLinx, I keep seeing all my SLC dropping in and out of the network every few seconds. All the SLC seems to drop out one after another and then it will come back on. My next step is to remove the DH+ connection to the 1785-KA5 bridge and see if they stabilise. Other than that, I am at a lost. Anyone had similar experience? Thanks.

Hi Scott, Most employers would not hire you unless you are in Australia and have a visa that allow you to work here. It might be a good idea to go to the immigration website and see what type of visa you can qualify for. However, if you want to try looking for a job first, you can check out these jobs website: Mycareer or Seek. Good luck

I've done some PLC2/30 upgrades and I can share some insight to what I've done: 1. I removed the PLC2 and replaced it with a 1771-ASB, effectively making that chassis a remote i/o chassis. I hooked the RIO bus to a nearby PLC5. Dip switches on the backplane have to be set as well. 2. Using a Rockwell Software, I converted the PLC2 ladder to RSLogix 5. Conversion was simple and straighforward. 3. Point to note: TON and TOF in PLC2 have 3 time base 0.01,0.1 and 1 sec. In PLC5, only 2 time base, 0.01 and 1. It can create a bit of a problem, timing wise, if you are not careful. 4. PLC2 doesn't start with Rack 0, so the first rack is Rack 1. After conversion, that rack is still Rack 1. My PLC5 has already a Rack 1, so I have to change the configuration for the PLC2 chassis to Rack 10 ( Rack 1 thru 7 was taken) or some other rack higher than 1. 5. The converted PLC2 logic was added as a ladder file in the PLC5 logic. To convert PLC2 to ControlLogix, you can use the translate tool in RSLogix5000 to convert from RSLogix5. I've done this before, but have not commissioned the code. So I can't tell if it is working according to the original logic. For PLC3 to ControlLogix, from what I've heard, is a bit more tricky. My colleagues told me there isn't a conversion software available. However, Rockwell in US can do the conversion, for a fee, of course. Just sharing my experience. Cheers.

I did a quick search on the net and found out that there are many acronyms refering to the same thing. RCDs (Residual Current Devices), common usage in Australia RCCBs (Residual Current Circuit Breakers), common usage in Australia ELCBs (Earth Leakage Circuit-Breakers), common usage in Singapore, Malaysia CBRs (Core Balance Relays), I don't really know where it is commonly used GFIs (Ground Fault Interrupts), common usage in USA GFCI ( Ground Fault Circuit Interrupter), common usage in USA

I've seen similar problem. There was a system which uses Citect SCADA to get parameters from PLC, do a bit of claculation, and sent it back to PLC. So in the end, we get 2 platform that must not fail. The PLC or the Citect, must not fail. I think this is ridiculous. A good control system would allow the system to function safely when the SCADA is down.

I use to work for a big multinational corporation and there was an engineering section that is repsonsible for creating HMI applications. They ( and I was subsequently seconded to that group for 1.5 yrs) uses Cimquest InGear32 to write applications in VBasic and C++ to interface to ControlLogix. We were very succesful in implementing this HMI to our factory floor worldwide. In retrospect, I think it was not a good move to create a team just for that. We could have easily use existing HMI or SCADA packages off-the-shelf and same heaps of dollars. Why re-invent the wheel, right?

I studied Mechatronics, a hybrid course in Mechanical, Electrical and Electonics. I am not saying I am a good controls engineer, but this course has given me a good grounding of the key components in automation engineering. It provided me with good understanding of mechanical principle in fluid dynamics, pneumatics and applied mechanics. The electrical portion give you knowledge in electrical power, motor controls, 1-ph and 3-ph power. The electronics portion deals with microprocessor, embedded programming and included as part of the Mechatronics program is software engineering. Most importantly, in-all three branches of engineering, we were trained in control engineering (Bode-plot, etc.) IMHO, Mechatronics program is tailored specifically for engineers that want to go into the automation or controls field.

Hi Sp4rky, You might want to check out Promis-e from ECTI. It is a CAD system purpose build for Control Engineers ( include panel layout, automatic wire numbering, costing, etc, etc.). For wire numbering, I believe that US and EU has their own wire color code, so be aware of the wire color convention. As for wire numbering, I've seen some companies prefer to have their wire number referenced to drawing number-line number (. eg. 12317 means sheet 123 line 17) and some prefer to have PLC I/O number referenced on their wire numbers ( eg. O00101 menas Output 001 Bit 01). Personally, I prefer the drawing-line number reference.

And you might want to check the RSLogix version. RSLogix5000 version 12 would work ok with RSLogix Emulato 5000 version 12 and RSLogix5000 ver13 works well with Emulator 5000 v13.

Sorry..that was me who posted as Guest. I didn't realise that I wasn't logged in.

..excerpt from Data Highway/Data Highway Plus/Data Highway II/Data Highway-485 Cable Installation Manual Hope this help.

Thanks for the tips. I went around the plant to check the cables and terminations, all seems to be in order. The electrician had a round the previous shift and had tightened and check all cabling, it seems. However, I found something interesting. The RackStatus bit goes high just before a solenoid valve opens. We will check this out today to see if the RIO is affected by the noise from the solenoid. I'll keep you posted.