Equipment to delay a RS422 connection

Where can I find a piece of equipment that can delay a RS422
connection?
Ideally the delay should only work one way i.e. the Tx should be
delayed and the Rx should not be delayed. The delay should be
adjustable in the range 0-40 ms.

Thanks for any help.

Peter

Peter Thomsen

"Peter Thomsen" <> wrote in message
news: m...
> Where can I find a piece of equipment that can delay a RS422
> connection?
> Ideally the delay should only work one way i.e. the Tx should be
> delayed and the Rx should not be delayed. The delay should be
> adjustable in the range 0-40 ms.
>
> Thanks for any help.
>
> Peter

More Info Please?

Why are you delaying the signal and for what purpose?

Inquiring minds want to know...

Jay In AZ

In article <> ,
(Peter Thomsen) wrote:

> Where can I find a piece of equipment that can delay a RS422
> connection?
> Ideally the delay should only work one way i.e. the Tx should be
> delayed and the Rx should not be delayed. The delay should be
> adjustable in the range 0-40 ms.
>
> Thanks for any help.
>
> Peter

Hmmm.. Me puzzled. Why???????

In article <alann19->,
Alan N <> writes:
> In article <> ,
> (Peter Thomsen) wrote:
>
>> Where can I find a piece of equipment that can delay a RS422
>> connection?
>> Ideally the delay should only work one way i.e. the Tx should be
>> delayed and the Rx should not be delayed. The delay should be
>> adjustable in the range 0-40 ms.
>>
>> Thanks for any help.
>>
>> Peter
>
> Hmmm.. Me puzzled. Why???????

Indeed.
Setting the bitrate to 200bits/sec will give you a 40ms delay
for 8 bit characters. Higher bitrates will reduce this
proportionally. Of course, this will vary the throughput as
well as the transit delay, but without any clue why you want
to do this, I've no idea if that matters.

--
Andrew Gabriel

(Andrew Gabriel) wrote in message news:<brs0ja$s9b$>...
> In article <alann19->,
> Alan N <> writes:
> > In article <> ,
> > (Peter Thomsen) wrote:
> >
> >> Where can I find a piece of equipment that can delay a RS422
> >> connection?
> >> Ideally the delay should only work one way i.e. the Tx should be
> >> delayed and the Rx should not be delayed. The delay should be
> >> adjustable in the range 0-40 ms.
> >>
> >> Thanks for any help.
> >>
> >> Peter
> >
> > Hmmm.. Me puzzled. Why???????
>
> Indeed.
> Setting the bitrate to 200bits/sec will give you a 40ms delay
> for 8 bit characters. Higher bitrates will reduce this
> proportionally. Of course, this will vary the throughput as
> well as the transit delay, but without any clue why you want
> to do this, I've no idea if that matters.
Yes, I know it is a rather strange requirement.

The matter is to align the command sent to a video switcher, with the
play command send to a video server. This to make sure that the On-air
transition from one programme to the next takes place without spurious
pictures of one video frame.

What I forgot to mention is that bit rate is 19.2 kbit/s or 38.4
kbit/s

Still hoping for useful hints.
Peter

Peter Thomsen wrote:
>>>>Where can I find a piece of equipment that can delay a RS422
>>>>connection?
>>>>Ideally the delay should only work one way i.e. the Tx should be
>>>>delayed and the Rx should not be delayed. The delay should be
>>>>adjustable in the range 0-40 ms.

I recall that circuit designers sometimes use a long piece of wire to
delay a signal a specific amount of time.

I don't recall the formula, but I wonder how long the wire would need to
be to delay the signal 40ms. I know that electricity travels through
wires much slower than the speed of light, but I still suspect it may be
too long.

-Z

In article <brvgsp$b0s$>, says...
> Peter Thomsen wrote:
> >>>>Where can I find a piece of equipment that can delay a RS422
> >>>>connection?
> >>>>Ideally the delay should only work one way i.e. the Tx should be
> >>>>delayed and the Rx should not be delayed. The delay should be
> >>>>adjustable in the range 0-40 ms.
>
> I recall that circuit designers sometimes use a long piece of wire to
> delay a signal a specific amount of time.

Sometimes. I've seen memory made out of long hunks of coax cable.
Launch a serial string at one end wait for it to come out the other and
re-launch it. When the data of interest comes around take it or update
the string.
>
> I don't recall the formula, but I wonder how long the wire would need to
> be to delay the signal 40ms. I know that electricity travels through
> wires much slower than the speed of light, but I still suspect it may be
> too long.

Most wire is about 50% slower than light or about 1.5ns per foot. Your
40ms wire would be ~5000 miles long.

--
Keith

"Peter Thomsen" <> wrote in message
news: m...
> (Andrew Gabriel) wrote in message
news:<brs0ja$s9b$>...
> > In article <alann19->,
> > Alan N <> writes:
> > > In article <> ,
> > > (Peter Thomsen) wrote:
> > >
> > >> Where can I find a piece of equipment that can delay a RS422
> > >> connection?
> > >> Ideally the delay should only work one way i.e. the Tx should be
> > >> delayed and the Rx should not be delayed. The delay should be
> > >> adjustable in the range 0-40 ms.
> > >>
> > >> Thanks for any help.
> > >>
> > >> Peter
> > >
> > > Hmmm.. Me puzzled. Why???????
> >
> > Indeed.
> > Setting the bitrate to 200bits/sec will give you a 40ms delay
> > for 8 bit characters. Higher bitrates will reduce this
> > proportionally. Of course, this will vary the throughput as
> > well as the transit delay, but without any clue why you want
> > to do this, I've no idea if that matters.
> Yes, I know it is a rather strange requirement.
>
> The matter is to align the command sent to a video switcher, with the
> play command send to a video server. This to make sure that the On-air
> transition from one programme to the next takes place without spurious
> pictures of one video frame.
>
> What I forgot to mention is that bit rate is 19.2 kbit/s or 38.4
> kbit/s
>
> Still hoping for useful hints.
> Peter

Peter, try posting your question to news://sci.engr.television.broadcast
Someone there may be able to help.

Cameron

"Cameron Dorrough" <> wrote in message news:<bs54gd$ro5$>...
> "Peter Thomsen" <> wrote in message
> news: m...
> > (Andrew Gabriel) wrote in message
> news:<brs0ja$s9b$>...
> > > In article <alann19->,
> > > Alan N <> writes:
> > > > In article <> ,
> > > > (Peter Thomsen) wrote:
> > > >
> > > >> Where can I find a piece of equipment that can delay a RS422
> > > >> connection?
> > > >> Ideally the delay should only work one way i.e. the Tx should be
> > > >> delayed and the Rx should not be delayed. The delay should be
> > > >> adjustable in the range 0-40 ms.
> > > >>
> > > >> Thanks for any help.
> > > >>
> > > >> Peter
> > > >
> > > > Hmmm.. Me puzzled. Why???????
> > >
> > > Indeed.
> > > Setting the bitrate to 200bits/sec will give you a 40ms delay
> > > for 8 bit characters. Higher bitrates will reduce this
> > > proportionally. Of course, this will vary the throughput as
> > > well as the transit delay, but without any clue why you want
> > > to do this, I've no idea if that matters.
> > Yes, I know it is a rather strange requirement.
> >
> > The matter is to align the command sent to a video switcher, with the
> > play command send to a video server. This to make sure that the On-air
> > transition from one programme to the next takes place without spurious
> > pictures of one video frame.
> >
> > What I forgot to mention is that bit rate is 19.2 kbit/s or 38.4
> > kbit/s
> >
> > Still hoping for useful hints.
> > Peter
>
> Peter, try posting your question to news://sci.engr.television.broadcast
> Someone there may be able to help.
>
> Cameron
Thanks I will do that right away - Peter