How To Use Usb To Rs232 Converter
Tonja Witcraft
Obviously I should not have to cross my lines to get it to work, as it works just fine using the usb to RS232 cable (first two pictures) without crossing the lines. This leads me to believe the problem is within the converter itself maybe? However, when I use the usb-RS232 cable and putty to send the photon data, it works just fine
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So, does anyone have any ideas on how to remedy this? Why do all the pieces work separately but not together? Also, I am fairly new to this language so coding tips are always appreciated! Thank You! Attached are some more pics of my set up:
And you are correct that I am bypassing the shifter on the board when I am using it to send data to putty. Because the wire is open ended, I wanted to just use the female RS232 end of the board as a means to create a direct connection from the sensor to my computer, just to ensure that the senor is streaming data correctly and to see what format it is coming out as. Essentially for that test I was just creating a female rs232 end to my wire.
So thinking about it now, if this set up (for bypassing the shifter) works then data is streaming into pin 2 on the female end as outgoing data and being received on pin 2 on the male end (as it is supposed to, right?). But then if I need data to be streaming into my female pin 3 for the shifter to work, I would have to cross the wires as @ScruffR suggested. My bad ScruffR, took me a while to get my head wrapped around this one.
The logical explanation is you are connecting the two wires works because by soldering them together you are connecting the wire transmitting the data from the meter to the pin it actually wants to go to on the MAX3232.
Also what voltage is 0.130V and why do you think that is good?
I found the data sheet for the chip that should be on it for you.
I would suggest tracing the connectors and see if its wired correctly.
It might even be easier to get your own MAX232 or similar and build your own if its still doing strange things
@dpstring, a null modem is nothing other than a RX/TX cross-out connector
en.wikipedia.org Null modem No hardware handshakingThe simplest type of serial cable has no hardware handshaking. This cable has only the data and signal ground wires connected. All of the other pins have no connection. With this type of cable flow control has to be implemented in the software. The use of this cable is restricted to data-traffic only on its cross-connected Rx and Tx lines. This cable can also be used in devices that do not need or make use of modem control signals.
Following picture depicts the instrument and the connecting cable with converter which I am trying to use in this setup. I think previously, I have used wrong nomenclature for these components and that why I prefer to attach the corresponding pic.
Until recently, I haven't had to connect to a piece of hardware using a serial connection in quite sometime. Well, that all changed yesterday when I needed to connect to a Watlow F4T Controller. I dug around in the bottle drawer of my desk and pulled at not one, but two USB-Serial Converters that I saved for just such an occasion! My old ones worked on everything from Allen Bradley SLCs, to Schneider Drives. Unfortunately, neither appear to work in a Windows 10 environment. Searching the internet, I was not able to find any drivers for these old converters, but did find some posts in another forum stating that Microsoft changed how it manages its USB ports from Win 7 to Win 10. Thanks Microsoft! Sorry, I will cut this rant short and just ask my question.
You will have to get the usb cable seperate. This worked for me on numerous different automation equipment. I can not gurantee it will work with your specific unit, but might be worth a shot. Little note: Be careful when choosing the usb cable as you can choose 2.0 or 3.0. Sometimes the 3.0 cables do not work in my experience. The 2.0 cable would probably be your best bet.
My go-to USB-serial adapter has been the Keyspan (Tripplite) USA-19HS for over a decade. This thread made me realize that I'd never tested it in Windows 10, so I just did. It took a reboot and a few tries in RSLinx Classic, but I did get it to connect to a SLC 5/05's serial port. I've used it in the past to connect to a Watlow F4 as well, but using Windows 7 on a different laptop.
So, a quick followup. I opened up my Win10 VM again this morning and tried to connect to the 5/05 but RSLinx couldn't get the COM port, said it was busy. The Keyspan utility showed it bouncing between idle and busy about every second. I ended up having to delete the driver in RSLinx and set it up again from scratch. Even so, auto-configure took several tries to work. I fired up my Win7 VM (same Win10 host) and it connected and worked out of the box with no issues. There may be an issue with the Keyspan driver (I'm using the latest one) or with how Windows 10 is handling things. I'll definitely be keeping my Win7 VM...
What is looping back?
I applied 5v through a 220 ohm resistor on TX pin on TTL side but there is no 5v on TTL RX pin (around 500-600 mV), and current measured on RS232 side is on RXD pin around -9v, and when I connect RS232 to RS232 to TTL converter, some blinking starts taking place without any external voltage source (arduino etc), maybe my coverter is broken! Please do suggest what should I do now?
Your help will be highly appreciated, My other hardware and code is ready and now I am stuck in this situation! Please do suggest any type of communication or circuit which I can use, I have MAX3232 in case my converter doesnot work
I have connected TX to 5v arduino output through 220 ohm resistor and TTL GND to arduino GND and VCC to arduino 5v and measuring voltage through RX pin from TTL converter gives 5v, and also connecting RX to TX pin of RS232 connection.
I got this usb rs232 converter and I was wondering if somebody knows if it is possible to use this (or any other usb rs232 converter) without using the drivers. The converter I got has a FTDI chip and it does have drivers included, but I want to use it without the drivers because I plan to connect it to an Arduino and a serial printer, and not a computer, so there is no operating system for the drivers.
I cannot give you too much guidance on what you are doing but, you might want to consider using a MAX232 chip or a serial adapter like our Pololu 23201a Serial Adapter. Using a device with a USB connection seems like it would be very complex and probably not the way to go.
After a lot of research and experimenting I can now answer my own question Apparently it is impossible to use a USB serial adapter without having an operating system at the USB end where the drivers can be installed. In other words, a USB serial adapter cannot convert data without drivers. Correct me if I am wrong, but this is what I have concluded so far. I actually find it strange that no converter exists where the full conversion is made inside the converter, without the need for an operating system.
You may be surprised by the amount of code involved. For examples of what is required on the device end (source code included), there are two open source projects for AVR processors that I know of. One is the software-only V-USB project fourwalledcubicle.com/LUFA.php
Maybe this is my problem.
In Visilogic, there is always a modem running on Com1,
when I hang up, the modem stops for a very short time, but automatic dial again?
I cannot stop the modem nor edit the data?
Which connection does Visilogic use?, Serial or Modem?
This doesn't really make any sense
Type any symbol in TX and send it to port - you must see the same symbol in RX menu. If you do not see sended symbol in RX display - your hardware-software configuration is not correct or Ethernet to RS232 adapter is damaged.
My input on this is that the reference to the modem you are seeing is there all the time, but users don't often notice it. I've always figured it's the way the connection is done internally in Visilogic. If connections are slow, you can see it very briefly on disconnect and then it disappears. I would suggest that you go into Connection/Modem services and choose a com port there that is not used in your PC at all. Ensure it is not the one designated in Visilogic for your normal serial work, and is a free one by making sure hidden connections are also shown when using Device Manager. For me this hasn't made a difference, but at least it ensures there is no potential conflict going on and it is still simply Visi doing it's thing.
My thoughts on the connection issue is that the Gnome is too sophisticated to do the job wanted. In particular, the web page you've linked to says it needs configuration via the web interface. Way too clever for what is needed!! You want a simple usb to serial converter based on the Prolific chip. If you query google using "Prolific USB to serial converter" you'll find lots of options.
And a PS to all of it. For the price of the gnome you could easily get an old laptop with a native serial port. Many users on the forum have such things, purely used for the multiple older systems we service that only use serial. It's a constant issue faced with newer PCs/laptops etc. Makers ignore the fact that serial ports are still needed by many people in the real world, but because it's an "older, out of date" comms method they don't include them. Grrr.
In my workplace we use an old software that accepts keyboard input, but only from a keyboard that's connected to a COM port. We have an old converter that has a PS2 keyboard input and converts it to RS232 which then connects to the computer.
Because these converters aren't cheap and we already blew a lot of money on this, I wanted to ask here if this solution will work or do you guys know any other solution that might work. We really tried everything and haven't found any solution, but I really believe there MUST be an easier way to perhaps trick the computer into thinking we connected a keyboard to it's COM port even though it's USB keyboard, even something like a software emulator.
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