RS-232C vs RS-232

[adam]

Hi anyone,

Is there any difference between(RS232) and (RS232-C) protocols? Please tell me details if possible.

Any help on this would be kindly appreciated.

Thanks in advance.

[Rudi]

Some info from the web...

In telecommunications, RS-232 (Recommended Standard 232) is a standard for serial binary data signals connecting between a DTE (Data terminal equipment) and a DCE (Data Circuit-terminating Equipment). It is commonly used in computer serial ports. A similar ITU-T standard is V.24. The Electronic Industries Alliance (EIA) standard RS-232-C as of 1969. (Quoted from: https://itknowledgeexchange.techtarget. ... rs/rs-232/)

For more detail on RS-232C, see: https://searchnetworking.techtarget.com ... on/RS-232C

If this is handy, see also: 3 EASY STEPS TO UNDERSTAND AND CONTROL YOUR RS232 DEVICES.

[adam]

Thanks very much for the information Rudi.

[adam]

I have;
1. An instrument which has a male Rs232 output port.
2. A rs232 cable of which both ends are female
3. A rs232 to usb cable where the rs232 end of the cable has male pins.

One end of the rs232 cable with both female ends is connected to the machine. The other end is connected to the rs232 end of the rs232 to usb cable. The usb end is connected to my laptop.

The laptop shows that the connection is established. However when I try to transfer the data the machine gives me the error message that the cable is not correctly connected or there's a problem with the connection.

All the cables are new and do not have any problem.
What might be the reason for this.

Should it be because the wiring of male to female is not matching?

[Rudi]

I'll have to hand this over to someone else.
I have no experience on the hardware side of PC's. Sorry.

[Leif]

Assuming you are talking about 9-way D-Types, a few things to try:

1. Check if the F-F cable is a cross-over cable. Pin 1 of one end should go to Pin 1 of the other, Pin 2 to Pin 2, etc. If they do, it is not a cross-over cable.
2. Try a cross-over cable - this should have pins 2 & 3 reversed (2 goes to 3, 3 goes to 2)
3. Check that the F-F cable is fully wired - i.e. all 9 connections are wired. (The communications may or may not need all pins connected.)
4. Check you have the protocol set up correctly at both ends; baud rate, stop bits, flow control, etc.

(More info on pinouts at https://www.db9-pinout.com/" onclick="window.open(this.href);return false; )

The laptop shows that the connection is established.

I suspect this just means that the laptop can see the USB-RS232 converter chip as a port, and not that it is talking or connected correctly to your equipment.

However when I try to transfer the data the machine gives me the error message that the cable is not correctly connected or there's a problem with the connection.

Is the "machine" you refer to the 'instrument' you mention or your laptop?

[adam]

Thankyou very much Leif for the recommendations and instructions. Now cable works fine and the data gets transferred accordingly.