adccommunitymod (AutomationDirect) asked a question.
Created Date: March 14,2007
Created By: BretB
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I am looking at getting a H2-EBC, a D2-046-1 with a D2-16 port and a PC-KEPEBC-7. In English that's a 4 slot base with an Ethernet Base Controller, a DC power supplier for the inputs, and an Ethernet I/O Server from Automation Direct. I went over this with my IT guy and we need to know what format, or in what state does the data come from the PLC unit, to the software that first will read the data. By the way, we are setting up a system that will simply take the states of the switches these PLCs are monitoring and reading them and sending their state to our computer network. That's it. Very simple. So we just need to know how the data comes from the hardware over to the software. We can then proceed to make our software to read it. Thanks.
Created Date: March 14,2007
Created by: KPrice
BretB, The 4-slot base with the EBC requires PC-based control. Check the Ethernet Software Development Kit from Host, www.hosteng.com
Did you look at a D2-260 CPU-controlled 4-slot base with an Ecom module, H2-ECOM100, and the Ecom I-box instructions? Hope this helps.
Created Date: March 14,2007
Created by: Tech Guy
BretB, the PC-KEPEBC-7 is an OPC server which specifies the format that the data will take.
If you are writing a Visual Basic program to handle the data, you can find an exmple over at Kepware Support .
Created Date: March 14,2007
Created by: stimpsonjcat
I do not see an IO module part # listed, what module are you using?
Typically the KEPEBC package will map the IO for each card in several different format options (bit, byte, word)
Created Date: March 17,2007
Created by: BretB
I don't have a module yet, I am looking to buy one and I am checking out where and what to buy.
I will need a non-Win32 based control, or that would be easiest.
The main thing I would really need to know, is what format does the input come from the PLC to the PC in?
If anyone knows the raw bits and bytes to this - how (in what form) does this data arrive to the computer from the I/O module or PLC, that will help.
The IO module I had spec 'ed was the PC-KEPEBC-7. But I don't know if that will work based on the fact that I have to have a DDE or OPC data exchange format with this thing.
-Bret
Created Date: March 18,2007
Created by: bcarlton
1. Your part numbers are confused. Please restate the exact AutomationDirect part numbers. Your 'd2-046-1 ' appears, from your description to be a 'd2-04B-1 '. It is not clear what you mean by a 'd2-16 port '. Are you referring to one of the 16 point input or output modules? If so please give the exact part number of the module.
2. Your PC software, 'PC-KEPEBC-7 ', (not an 'I/O module ' in the ordinary sense of the term) will provide the OPC interface via an Ethernet communication network to the H2-EBC controller. That controller is communicating with whatever I/O modules you choose to place in the rack.
3. The nature of the I/O information will depend on the type of modules you choose. Discrete input modules will provide point On/Off status. Discrete output modules will translate On/Off commands into a switched On or Off state on their outputs. Analog mudules generally provide and recieve information as numeric words which are related to the analog value they are measuring or controlling. The format of these numbers will be explained in the information for these modules.
4. Your client application (which resides on the same PC as the KEP software) will provide the output instructions and receive input information. The communication between your client software and the KEP OPC server will need to comply with OPC guidelines. I'm sure that the software will come with examples.
The online setup manual http://web5.automationdirect.com/static/manuals/dakepm/dakepm.html
may provide some insight into your questions.
Created Date: March 18,2007
Created by: BretB
The trouble is, I don't know the exact part numbers I need. The ones I was trying to say may be wrong.
Those 16 point modules would be input, because I will have over 100 inputs and one "output " to a computer.
I will be using manual On/Off switches, like light switches that are either open or closed for my input.
I downloaded the tri-plc demo version of the ladder logic programming sofware, and I'm realizing more and more that what I am doing is SO simple, it seems like I need more of a "signal collector, and communicator to the computer " rather than a "programmable logic controller ".
Literally the diagram that would control the flow from the switches (inputs) to the computer or central PLC or whatever (output) are ALL STRAIGHT LINES from left to right across the ladder logic programming screen.
There is not one bit of "logic " needed or in it at all. It's just "switch 1 is on, oh, that means that output 1 should be on " and "switch 16 just turned off, now that means that output 16 should be turned off ".
That is literally the extent of it.
It seems that a PLC is overkill here. Or am I missing something?
Created Date: March 19,2007
Created by: bcarlton
In one view it's overkill since you could obviously wire each switch to its own output device and be done with it. But there's obviously more to it.
In your post you mention 'over 100 inputs and one "output " to a computer '. But then later on you mention input 16 affecting output 16. This seems contradictory.
Is the system so proprietary that you can't mention more about the design? If you could perhaps those reading this thread could suggest a more practical setup.
So far the parts that you have mentioned would give you access to a rack which is remote from a PC. A process running on the PC would receive information and control conditions on the rack by means of the KEP communication software via Ethernet to the EBC interface.
Created Date: March 19,2007
Created by: BretB
On the overkill point, I guess I just drop the CPU and then it's not overkill. I don't need to "process " any information.
What I meant by the "16 " was simply any random switch in the lot of them, it could be number 99 being switched ON, then it recognized by the IO board and the signal that switch 99 is "ON " is relayed to the computer. The same with switch number 1, when it's switched "ON " the computer just needs to get notified that switch #1 = ON. Then when it's off, the computer needs to get notified that switch #1 = OFF. Sorry, I'm new to PLCs and I shouldn't have used the word "output 16 " earlier. One output to the computer was more correct.
I spent some time today pouring through the AD catalog and the following are the parts that we are looking at getting FOR DEVELOPMENT AND TESTING. I know that they will not be sufficient for our 100+ switches, but it will get us started and we should be able to work out the interface between our software (being programmed in Java) and the IO module.
Our current spec is:
DL 205 4-slot base
H2EBC Ethernet Base Controller
16ND3-2 DC Input (16 inputs)
PSP24-024s Power supply
That leaves me two expansion slots for later another 16 input card and a D2-EM expansion port to connect to the next module on the next floor to cover the next set of switches.
By the way, what would be the proper name for a unit like this? It's not necessarily a PLC as there is not going to be any programming or logic other than "relay the 0's and 1's to the computer, assigned to their proper switch name ".
You left this point of "overkill " kind of open. Based on your knowledge and experience , do you think the above is overkill, or suitable? If overkill, any recommendations as to a more elegant or efficient solution?
As to your request for more information on the design, I think I 've covered what is necessary. I apologize for the lack of lengthy explanation, however it is a bit sensitive to put on a open forum.
Thanks for your help.
- Bret
Created Date: March 19,2007
Created by: Wiseman
I don't know the cost but you might try using a digital I/O card that installs in a PCI slot in a pc. I 've not used this brand before but it appears they supply a 96 point I/O card.
http://www.accesio.com
Created Date: March 19,2007
Created by: bcarlton
I guess the next question would be - what is the physical layout of the switches relative to the processing PC? Are they remote? This would require some type of setup such as you are mentioning. The KEPEBC-7 would allow up to 7 remote stations, each with its own rack and EBC interface.
If the switches are local to the PLC (within a few feet) then an input card (such as Wiseman suggests) within the PC could be of better use.