adccommunitymod (AutomationDirect) asked a question.
Created Date: March 16,2010
Created By: Tubecut
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I can not measure the 5 VDC when connecting a EA-MG-PGM-CBL (USB Serial adaptor) using a DV-1000CBL to a ZIPLink module (ZL-CDM-RJ12X4). This is checking all pins to each other. If I connect the USB serial adaptor direct to the CMore Micro, then it firs up and works OK. Using a second DV-1000-CBL connected to the same ZIPLink with the serial adaptor in one RJ12 connector and another DV-1000-CBL plugged into an adjacent RJ12 connector, the connection from adaptor to CMore Micro doesn’t work. So, there is something I don’t understand and attempting to understand. I also tried using a second ZipLink R12X4 and wired TB1 between the two . I wired the connections one to one and reversed as well. No comm. to/from the Cmore Micro. I am hoping someone can get me straight on this.:o Thanks in advance.
Created Date: March 16,2010
Created by: bcarlton
The DV1000-CBL is a swapping cable - 1-6, 2-5, 3-4 etc. To use the USB adapter through the ziplink one of the two RJ12 cables would have to be a straight through, 1-1, 2-2 etc
Created Date: March 17,2010
Created by: Tubecut
Yes, I understand that the cable is a reversing cable. But, I still don't understand why the 5 VDC never shows up at.:confused:
This is just plugging the USB adapter to the ZipLink and checking at each of the pins and pin by pin to each other. I checked the ZipLink as well and the TB connectors all test to each pin in the RJ12 connector. (Used a real skinny probe). I do measure a -9.91 between pin1 and pin 3 (at the TB) This is a valid RS-232 voltage, so that looks correct to me.
Also, using the TB connectors, I wired up a separate cable to a DB9 and then tested the adapter and DV-1000 cable by using a terminal program and another serial device, worked fine.
The only thing I can come up with is that somehow the adapter and driver must 'see ' something at the other end to enable the 5 VDC to turn on.
All said, it doesn't really make a lot of difference , I know the cable is good, the adapter and the Cmore Micro are all good, just couldn't except that I could not see the 5 VDC. Just an academic interest.:D
Well, thanks for the response bcarlton.
Cheers
Created Date: March 17,2010
Created by: Tubecut
As I have two each DV-1000-CBL and two ZL-CDM-RJ4X modules I tried wiring between the two ZipLinks as per the attached PDF. Doesn't work in either configuration. I am sure I don't have something correct here, just don't see it.:o
Created Date: March 17,2010
Created by: Do-more PE
RS-232 won't work that way. You would need to use RS-422 or RS-485 in order to get that type of configuration to work. Take a look at the spec sheet , first paragraph at the top.
Created Date: March 17,2010
Created by: Tubecut
I think you might have misunderstood what I was trying to ask.
The attached drawing shows two different configurations using two each ZipLink modules and two DV-1000-CBL set up.
But, nothing yet has explained why the 5 VDC is not measured at the terminal block with just a DV-1000-CBL attached to the USB adapter and nothing else attached.
I am thinking that I should be able to 'see ' that DC voltage.
I don't think anyone really knows why, certainly not me.
Created Date: March 17,2010
Created by: bcarlton
I know that USB has to see a connection of some type to put out the 5V but the USB to RS232 adapter is that connection. Possibly something in that adapter does the same type of trick ... if there isn't a load on the TX line then don't turn on the 5 volts? I guess we would have to know all about the internals.
I still don't see why your two adapters with swapped wiring between them and two DV-1000-CBL's didn't work. The adapters don't "KNOW " what is passing through. They don't care if it's RS232 or RS485, they 're just wire connectors. Unless there is something, other than just wires, on the adapters we don't know about.
Created Date: March 17,2010
Created by: Tubecut
Yes, I agree bcarlton. I don't know why one of the setups didn't work, but I do know that when I wire in to the TB with a DB9 pigtail and use a PC terminal program and connect to another serial device (a micro in this case), then I can use the USB serial adapter and it works perfect. Crazy, I still can't locate the 5 VDC, so it must be the driver likes a CMore better. I have also used the adapter with the CLICK (I think I did).
I don't think I need to go any deeper on this, it was mostly curiosity to as to why on 5 VDC from the USB port.
But, thanks for the interest and comments,
Best Regards
Created Date: March 18,2010
Created by: Do-more PE
The ZL-CDM-RJ4X are not designed to work with RS-232. They are designed for RS-485. The USB to serial adapter is an RS-232 device.
I would have to look at the schematic for the modules as to exactly why, but they are not designed to work with RS-232.
Created Date: March 18,2010
Created by: Tubecut
What has RS-232 got to do with the wiring, it is just routing wires?
As long as the conductors carry the signals from/to where they should go, then that is all that is required. You could probably use jumper cables to connect two devices RS-232.;)
Actually I did wire up a DB9 to the terminal blocks on the ZipLink module and it worked fine. Look at my previous post. It worked, RS-232 from the adapter to another serial (RS-232 device) using a terminal program like hyperterm to communicates with the serial device which in this case was a small micro board that was equipped with RS-232.
Cheers
Created Date: March 18,2010
Created by: bcarlton
I would have to look at the schematic for the modules as to exactly why, but they are not designed to work with RS-232
You provided the schematic in your link to the spec sheet.