Elecraft

Long RS232 Runs - RS422

Classic

List

Threaded

9 messages Options

Michael Walker

Long RS232 Runs - RS422

All

I wanted to mention that for those that want long RS232 runs for devices
(Steppir, Rotator, Elecraft Amp),

I have been using these commercially for some time with great success.
They are made in the US and are pretty reasonably priced at about $35
each. Of course, you need a pair of them.

Mike va3mw

http://www.rs485.com/prs422s.html

The RS422S is a fast Async bi-directional RS232 <=> RS422 interface
converter that will operate at data rates up to 115.2Kbps. The unit has
jumpers termination, RS232 DTE/DCE selection and, TTL/CMOS operation. The
unit has two RJ11/12 connectors an a pin header for power, common TTL/CMOS
TX data and RX data.

The RS422S is designed for office and/or indoor applications
(non-isolated). A pair of units and a 6-conductor reversing "telephone
style" cable can be used to form an RS232 "extension cord" for extended
operation beyond the RS232 specification.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Jim Brown-10

Re: Long RS232 Runs - RS422

On Thu,1/21/2016 10:32 AM, Michael Walker wrote:
> I wanted to mention that for those that want long RS232 runs for devices
> (Steppir, Rotator, Elecraft Amp),

It helps to define "long." Distance for RS232 was originally defined in
feet. Many years ago, it was redefined in terms of capacitance between
conductors. Using cables as common as CAT5, lengths of 200 ft or more
are no problem. Simply use one pair per signalling circuit.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Michael Walker

Re: Long RS232 Runs - RS422

I agree with Jim.

I have pushed long runs of RS232 at lower baud rates (4800) out to about
1000' for some temporary commercial applications.

Some of us just try it and see if it works, and others want to do what is
know to work.

Me, I'm a just try it type of person.

Mike va3mw

On Thu, Jan 21, 2016 at 1:44 PM, Jim Brown <[hidden email]>
wrote:

> On Thu,1/21/2016 10:32 AM, Michael Walker wrote:
>
>> I wanted to mention that for those that want long RS232 runs for devices
>> (Steppir, Rotator, Elecraft Amp),
>>
>
> It helps to define "long." Distance for RS232 was originally defined in
> feet. Many years ago, it was redefined in terms of capacitance between
> conductors. Using cables as common as CAT5, lengths of 200 ft or more are
> no problem. Simply use one pair per signalling circuit.
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Elecraft mailing list

Re: Long RS232 Runs - RS422

In reply to this post by Jim Brown-10

The old criteria was 50 feet, but that was set before the specification for any twisted pair for digital, let alone Cat 5. In short, it it works well, it is OK but 200 feet sounds reasonable. RS-232 uses a 5 volt signal level. RS-422 uses a higher signal level, I believe 12 volts, but that is from memory. Watch out for the serial dongles that plug into USB ports. Some are not full RS232 and do not work except with certain connections, ham radio applications not included. Be careful and if it does not work, keep trying different dongles or get on the internet and find the brand and source for one that will work. If all else fails or if you want to be sure, buy a card based RS-232 or 488 interface that uses all DB-9 or DB-25 connectors. Willis 'Cookie' Cooke,VP of Tidelands ARS and TXPE K5EWJ & Trustee N5BPS

From: Jim Brown <[hidden email]>
To: [hidden email]
Sent: Thursday, January 21, 2016 12:44 PM
Subject: Re: [Elecraft] Long RS232 Runs - RS422

On Thu,1/21/2016 10:32 AM, Michael Walker wrote:
> I wanted to mention that for those that want long RS232 runs for devices
> (Steppir, Rotator, Elecraft Amp),

It helps to define "long." Distance for RS232 was originally defined in
feet. Many years ago, it was redefined in terms of capacitance between
conductors. Using cables as common as CAT5, lengths of 200 ft or more
are no problem. Simply use one pair per signalling circuit.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Cliff Frescura

Re: Long RS232 Runs - RS422

RS-232 use +3 to +15VDC and -3 to -15VDC for signaling levels, thus -5 and +5 will work too, but *not* 0VDC and +5VDC

Like others, I've run RS-232 over 100's of feet. RS-422 will go much further and has the advantages of multi-drop and noise immunity due to its differential nature.

73,

Cliff K3LL

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of WILLIS COOKE via Elecraft
Sent: Thursday, January 21, 2016 11:53 AM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] Long RS232 Runs - RS422

The old criteria was 50 feet, but that was set before the specification for any twisted pair for digital, let alone Cat 5. In short, it it works well, it is OK but 200 feet sounds reasonable. RS-232 uses a 5 volt signal level. RS-422 uses a higher signal level, I believe 12 volts, but that is from memory. Watch out for the serial dongles that plug into USB ports. Some are not full RS232 and do not work except with certain connections, ham radio applications not included. Be careful and if it does not work, keep trying different dongles or get on the internet and find the brand and source for one that will work. If all else fails or if you want to be sure, buy a card based RS-232 or 488 interface that uses all DB-9 or DB-25 connectors. Willis 'Cookie' Cooke,VP of Tidelands ARS and TXPE K5EWJ & Trustee N5BPS

From: Jim Brown <[hidden email]>
To: [hidden email]
Sent: Thursday, January 21, 2016 12:44 PM
Subject: Re: [Elecraft] Long RS232 Runs - RS422

On Thu,1/21/2016 10:32 AM, Michael Walker wrote:
> I wanted to mention that for those that want long RS232 runs for
> devices (Steppir, Rotator, Elecraft Amp),

It helps to define "long." Distance for RS232 was originally defined in feet. Many years ago, it was redefined in terms of capacitance between conductors. Using cables as common as CAT5, lengths of 200 ft or more are no problem. Simply use one pair per signalling circuit.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Clay Autery

Re: Long RS232 Runs - RS422

In reply to this post by Jim Brown-10

This one is rated to 1250 meters... with CAT-3 cable (TELCO). Use
better cable and proper terminations and you MIGHT be able to extend
that a bit. Add an inline amp/repeater, and the distance could be
extended to... well... a long way...

How far you need to go?

73,

______________________
Clay Autery

On 1/21/2016 12:44 PM, Jim Brown wrote:

> On Thu,1/21/2016 10:32 AM, Michael Walker wrote:
>> I wanted to mention that for those that want long RS232 runs for devices
>> (Steppir, Rotator, Elecraft Amp),
>
> It helps to define "long." Distance for RS232 was originally defined
> in feet. Many years ago, it was redefined in terms of capacitance
> between conductors. Using cables as common as CAT5, lengths of 200 ft
> or more are no problem. Simply use one pair per signalling circuit.
>
> 73, Jim K9YC

Michael Walker

Re: Long RS232 Runs - RS422

For me at my remote, it is only 100ft, so I am using RS232 for the rotator
and the steppir.

For a big ski race in Kitzbuhel Austria, we pushed RS485 (1/2 duplex) 6000m
at 19200 without an issue.

Mike va3mw

On Thu, Jan 21, 2016 at 3:25 PM, Clay Autery <[hidden email]> wrote:

> This one is rated to 1250 meters... with CAT-3 cable (TELCO). Use
> better cable and proper terminations and you MIGHT be able to extend
> that a bit. Add an inline amp/repeater, and the distance could be
> extended to... well... a long way...
>
> How far you need to go?
>
> 73,
>
> ______________________
> Clay Autery
>
> On 1/21/2016 12:44 PM, Jim Brown wrote:
> > On Thu,1/21/2016 10:32 AM, Michael Walker wrote:
> >> I wanted to mention that for those that want long RS232 runs for devices
> >> (Steppir, Rotator, Elecraft Amp),
> >
> > It helps to define "long." Distance for RS232 was originally defined
> > in feet. Many years ago, it was redefined in terms of capacitance
> > between conductors. Using cables as common as CAT5, lengths of 200 ft
> > or more are no problem. Simply use one pair per signalling circuit.
> >
> > 73, Jim K9YC
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

David Woolley (E.L)

Re: Long RS232 Runs - RS422

In reply to this post by Cliff Frescura

The +/- 3 volts levels are requirements on the driver, not the receiver.
In practice, receivers have quite a small hysteresis, and the
threshold points are set to meet the requirements of a type 1 interface
as defined in section 7 of ITU-T V.28. Whilst the specified purpose of
this is that a powered down or open circuit condition should result in
defined states for, particularly control signals (off), in practice it
means that real world receivers will also handle high speed signals
which are strictly positive.

Consequently levels of +5 and 0 volts will, in most normal cases, work,
although they are out of specification.

ITU-T V.28 is generally aligned with the electrical characteristics of
EIA232, but has the advantage that the document is available for free
download.

--
David Woolley
Owner K2 06123

On 21/01/16 20:03, Cliff Frescura wrote:
> RS-232 use +3 to +15VDC and -3 to -15VDC for signaling levels, thus -5 and +5 will work too, but *not* 0VDC and +5VDC
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Cliff Frescura

Re: Long RS232 Runs - RS422

"Consequently levels of +5 and 0 volts will, in most normal cases, work,
although they are out of specification"

Yes, they work by accident. Until they don't.

73,

Cliff K3LL

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of David
Woolley
Sent: Friday, January 22, 2016 6:45 AM
To: [hidden email]
Subject: Re: [Elecraft] Long RS232 Runs - RS422

The +/- 3 volts levels are requirements on the driver, not the receiver.
In practice, receivers have quite a small hysteresis, and the threshold
points are set to meet the requirements of a type 1 interface as defined in
section 7 of ITU-T V.28. Whilst the specified purpose of this is that a
powered down or open circuit condition should result in defined states for,
particularly control signals (off), in practice it means that real world
receivers will also handle high speed signals which are strictly positive.

Consequently levels of +5 and 0 volts will, in most normal cases, work,
although they are out of specification.

ITU-T V.28 is generally aligned with the electrical characteristics of
EIA232, but has the advantage that the document is available for free
download.

--
David Woolley
Owner K2 06123

On 21/01/16 20:03, Cliff Frescura wrote:
> RS-232 use +3 to +15VDC and -3 to -15VDC for signaling levels, thus -5
> and +5 will work too, but *not* 0VDC and +5VDC
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]