Stackable switches

[Brct203]

Trying to schematize:
With the Rex it seems as follows (assuming, that the band and polarity command of diseqc 1.0 have no impact as yet (till you tested it otherwise)):

with diseqc 1.0=port1, you can reach diseqc 1.1 port 1/8 through command 1/8
with diseqc 1.0=port2, you can reach diseqc 1.1 port 1/8 through command 5/12
with diseqc 1.0=port3, you can reach diseqc 1.1 port 1/8 through command 9/16
with diseqc 1.0=port4, you can reach diseqc 1.1 port 1/8 through ...command 13/16 and 1/4????? (you didn't test or mention this yet).

I guess the diseqc 1.0 command was repeated, during this test? Or I don't see how the diseqc 1.0 command would otherwise reach and influence the 1.1 switch.
By the way. I know of no diseqc command, that could shift ports like is happening here. Very strange!


But with the Amiko, all is reacting normally, with this switch order? Does the Amiko have diseqc repeat?

greetz,
A33

on the Rex:
with diseqc 1.0=port1, i can reach diseqc 1.1 port 1/8 through command 1/8
with diseqc 1.0=port2, i can reach diseqc 1.1 port 1/8 through command 5/12
with diseqc 1.0=port3, i can reach diseqc 1.1 port 1/8 through command 9/16
with diseqc 1.0=port4, i can reach diseqc 1.1 port 1/8 through ...command 13/16 then 1-4

on the Amiko:
with diseqc 1.0=port1, i can reach diseqc 1.1 port 1/8 through command 1/8
with diseqc 1.0=port2, i can reach diseqc 1.1 port 1/8 through command 5/12
with diseqc 1.0=port3, i can reach diseqc 1.1 port 1/8 through command 1/8
with diseqc 1.0=port4, i can reach diseqc 1.1 port 1/8 through command 5/12

i could see sometimes some hesitation on the 1.1, where it would go to the port matching the command at first and then fall back on the port mentioned above. It seems that it's having some problems with the bits marking the 4 and 8 in the last nibble of the 1.1 command.

the repeat setting does not seem to have any impact. I did not inspect the actual commands on the Amiko so I don't know if there's any repeating

as to how it would reach, well, keep in mind that the DiSEqc commands are actually repeated at regular intervals, like every second or half second, so if it's not getting it the first time, it will get it on the next round

 

[a33]

.. keep in mind that the DiSEqc commands are actually repeated at regular intervals, like every second or half second,

Normally a receiver only sends a diseqc command when changing channels.
And only when that doesn't give a lock on the wanted channel, a receiver tries the diseqc command again, and repeats.
(BTW That is also important, because if 22kHz(continuous) is ON, a diseqc repeat would interfere with that.)

So I guess the repetition you mention is the 'no-lock repeat'. The interval for that is quite different over various receivers, I noticed.

greetz,
A33

 

[Keith Brannen]

Normally a receiver only sends a diseqc command when changing channels.
And only when that doesn't give a lock on the wanted channel, a receiver tries the diseqc command again, and repeats.
(BTW That is also important, because if 22kHz(continuous) is ON, a diseqc repeat would interfere with that.)

So I guess the repetition you mention is the 'no-lock repeat'. The interval for that is quite different over various receivers, I noticed.

greetz,
A33

That is not my understanding when it comes to cascading switches. The commands are sent more than once. For an explanation, see the below Spaun document (Page 7 starts the "Combination OF DiSEqC Components) 9.2.1 Example explains it.

http://www.spaun.com/files/8df79_en_DiSEqC_for_Technicians.pdf

 

[a33]

The commands are sent more than once.

That depends entirely on how the receiver's manufacturer has made it.
It can be once, or twice (or more), or settable by user.

The 'once' gives problems e.g. when cascading a 4/1 1.0 switch with a monoblock LNB (both switching on 'position' command).

And the lack of diseqc 1.1 repeat caused also a problem here, switching 20 LNBs in a rather special setup (sorry, in Dutch!): DISEqC, 20 lnb's schakelen

Not everything on the internet about diseqc is right. Also the wikipedia page about diseqc I find partly mis-informing, alas!
Even the eutelsat documents are not uptodate; some (motor)commands are missing.
The spaun document is indeed better than wikipedia. That sometimes repeats are needed is clear, but that doesn't mean that they actually happen.

Greetz,
A33

 

[Titanium]

Also consider that many receivers are coded to reissue 22KHz/DiSEqC commands if no signal path is detected for a tuner lock.

If signal lock is lost, many receivers attempt to reestablish the signal path. In your testing, it appears that no active transponder signal was available for tuner lock on each port. I would suspect that this would trigger command repeats by most STBs.

 

[a33]

That's about what I wrote in #62

greetz,
A33

 

[comfortably_numb]

Just to clarify, it would not be possible to stack two 4x1 switches, correct?

 

[a33]

Just to clarify, it would not be possible to stack two 4x1 switches, correct?

When they switch on the same commands: NO, pretty useless.
Only one port of the second switch would be reached; so the presence of the second switch would bring nothing.

When they switch on different commands: YES.
Can be done with a 4/1 diseqc 1.0 switch plus a 4/1 diseqc 1.1 switch.
Or with 2 4/1 diseqc 1.1 switches, that can be setup to use different uncommitted commandlevels (e.g. Spaun SUR420).
Or combined with a switch that switches on diseqc 1.2 commands.

8/1 switches I find easier than stacking two 4/1 switches; however with two dishes at separate locations stacking multiple switches could be easier.

greetz,
A33

 

[comfortably_numb]

I only see Diseqc 1.0 and 2.0 switches available that are of the 4x1 variety. Would one 1.0 and one 2.0 4x1 be stackable?

 

[Brct203]

I only see Diseqc 1.0 and 2.0 switches available that are of the 4x1 variety. Would one 1.0 and one 2.0 4x1 be stackable?

no they would not as they use the same commands (a 2.0 switch is like a 1.0 that can give feedback to the receiver)

 

[Keith Brannen]

That depends entirely on how the receiver's manufacturer has made it.
It can be once, or twice (or more), or settable by user.

The 'once' gives problems e.g. when cascading a 4/1 1.0 switch with a monoblock LNB (both switching on 'position' command).

And the lack of diseqc 1.1 repeat caused also a problem here, switching 20 LNBs in a rather special setup (sorry, in Dutch!): DISEqC, 20 lnb's schakelen

Not everything on the internet about diseqc is right. Also the wikipedia page about diseqc I find partly mis-informing, alas!
Even the eutelsat documents are not uptodate; some (motor)commands are missing.
The spaun document is indeed better than wikipedia. That sometimes repeats are needed is clear, but that doesn't mean that they actually happen.

Greetz,
A33

And my point was that a manufacturer (Spaun) of switches stated that when cascading switches the commands are required/need to be sent more than once for proper switching. Whether manufacturers of receivers follow those guidelines or not is at their peril as to whether they can properly control cascading switches if/when they don't follow those guidelines.

EDIT: If not sending the commands more than once, I can also see where a "no lock, repeat" could fail to happen if the command sent only once happened by chance to lock on a same frequency signal as the required channel.

 

[Brct203]

Update on my attempts at cascading diseqc 1.0 and 1.1.

Earlier in this threads I reported results of my unsuccessful attempts at cascading using a Pansat 1.1 switch.

Well, I recently bought a GeoSatPro 1.1 8-port switch, and now the cascading is working flawlessly.

So that would confirm a limitation in the Pansat 1.1 switch (but the Pansat works fine when used standalone, without cascading)