two diseqc switches

RidgeRunner

SatelliteGuys Pro
Original poster
May 30, 2005
172
30
Raymond, Maine, United States
I currently have two fixed dishes and I use a simple pansat 1.0 4x1diseqc to switch between the two and that's great. I want to swap out the LNB on one of my dishes with one of these DMS International Model: JSC-MB4-2
From what I under stand you can cascade switches but it would have to be 1.0 -> 1.1. or something of the like, but can't be 1.0 ->1.0. Does anyone know how I would achieve this with this LNB, it says it has diseqc built in, but little details on specially what.
 
The easiest way to do this, when you have still a free port on your 4/1 diseqc switch:
See the picture in this post: Due diseqc per un solo tuner
You would need a splitter or T-piece though; or solder a "bridge" inside the diseqc switch on the two output ports (the latter is the neater solution). I've had that working for years!
When your monoblock has two ports instead of one, it can also be done as in the picture in this post:

You could also use a diseqc 1.1 switch, or a special diseqc 1.0 OPTION switch. They are more expensive solutions...

Does this help?


Greetz,
A33


PS Do you want to read about it? This is the original thread: oplossing komb. monoblock/diseqC switch

Edit, PS2: Your receiver must issue a diseqc repeat for this above diseqc 1.0 solution to work. Most modern receivers do indeed repeat the diseqc commands....
 
Last edited:
The easiest way to do this, when you have still a free port on your 4/1 diseqc switch:
See the picture in this post: Due diseqc per un solo tuner
You would need a splitter or T-piece though; or solder a "bridge" inside the diseqc switch on the two output ports (the latter is the neater solution). I've had that working for years!
The solution where I do not need a open the switch and solder. I'd rather use the T. The monoblock I'm looking at only has one output port. So what I am confused about if the monoblock has one output and I use the T and go into two ports of my diseqc switch. I understand how to set my receiver up for two LNBs as I am already successfully doing that. What I'm confused about what dictates how to switch LNBs inside the monoblock. The information seems to indicate there is another diseqc inside the monoblock.
 
I'm sure a33 will correct me but let me take a stab at this.

With the T connector splitting your single output monoblock to ports 1 and 2 of your external switch.

  • When you select port 1, the external switch "opens" port 1, the port 1 command passes thru and the monoblock selects LNB 1.
  • When you select port 2, the external switch "opens" port 2, the port 2 command passes thru and the monoblock selects LNB 2.

This assumes that the receiver sends the specific DiSEqC commands more than once, which I believe is true.
 
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Still a bit of explanation:
One diseqc command is meant to make contact to one LNB only. Whether the proper connection to the LNB is made by one switch, or by a series of switches, is not important (just as with a light switch!).
In this case the path to diseqc port A or B of the monoblock LNB is first made in the external 4/1 diseqc switch, and then again in the monoblock itself, which indeed has a 2/1 diseqc 1.0 switch inside.

I've once tested this serial principle with a series of 7(!) switches. The switching went OK, but the signal was attenuated too much to have a picture....

The beauty of diseqc is that is you can use it for both serial, and parallel use. Very versatile!

So what I am confused about if the monoblock has one output and I use the T and go into two ports of my diseqc switch.
....
What I'm confused about what dictates how to switch LNBs inside the monoblock. The information seems to indicate there is another diseqc inside the monoblock.
With the 4/1 diseqc switch you can switch to ABCD.
A monoblock has indeed an internal diseqc switch for two ports.
You can use the AB commands for the monoblock (and by the way, CD for a second monoblock).
The monoblock must therefore receive both the A and B command. That is where the splitter on ports A and B of the external 4/1 switch comes in: in both cases it gives power and a repeated command to the monoblock.


Monoblock and diseqc: A monoblock is made to switch on the so-called POSITION command of diseqc 1.0 (committed).
That means you can reach the two LNBs of a monoblock:
with commands A and B,
or with C and D,
or with A and D,
or with C and B.
Your diseqc commands must follow the actual, physical, setup that you have.


I hope I've explained better, this time?


greetz,
A33
 
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With the T connector splitting your single output monoblock to ports 1 and 2 of your external switch.
  • When you select port 1, the external switch "opens" port 1, the port 1 command passes thru and the monoblock selects LNB 1.
  • When you select port 2, the external switch "opens" port 2, the port 2 command passes thru and the monoblock selects LNB 2.
This assumes that the receiver sends the specific DiSEqC commands more than once, which I believe is true.

Exactly!

(You posted while I still typed...)

Greetz,
A33
 
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I am thinking I have some understanding of how this stuff works, but I'm fuzzy on what exactly is meant by committed and uncommitted. Just found your post which explains it so no need to go thru it again here.
 
Last edited:
Diseqc 1.0 has four switching possibilities (16 switching states), which partly are connected to the older switching methods:
- Band (0/22kHz, "tone")
- Polarity (13/18V)
These two also work in "universal" LNBs, and in multiswitches.

- Position (toneburst, "simple diseqc", " mini diseqc"; often used in [old] monoblocks to switch between LNBs)

These three switching possibilities make the diseqc commands "committed" to the earlier switching. It is downward compatible, so to say.

A fourth switching possibility is:
- Option. This was the real new switching possibility for diseqc 1.0.

Normal 4/1 diseqc switches thus are position+option switches.


The complete transition to diseqc 1.0, and abolition of the old switching methods, never really took place.
The remaining downward compatibility still remains an obligation in the official diseqc protocol.


Diseqc 1.1 is fully UNcommitted: 16 switching states that you can freely choose.


Greetz,
A33
 
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Still a bit of explanation:
One diseqc command is meant to make contact to one LNB only. Whether the proper connection to the LNB is made by one switch, or by a series of switches, is not important (just as with a light switch!).
In this case the path to diseqc port A or B of the monoblock LNB is first made in the external 4/1 diseqc switch, and then again in the monoblock itself, which indeed has a 2/1 diseqc 1.0 switch inside.

I've once tested this serial principle with a series of 7(!) switches. The switching went OK, but the signal was attenuated too much to have a picture....

The beauty of diseqc is that is you can use it for both serial, and parallel use. Very versatile!


With the 4/1 diseqc switch you can switch to ABCD.
A monoblock has indeed an internal diseqc switch for two ports.
You can use the AB commands for the monoblock (and by the way, CD for a second monoblock).
The monoblock must therefore receive both the A and B command. That is where the splitter on ports A and B of the external 4/1 switch comes in: in both cases it gives power and a repeated command to the monoblock.


Monoblock and diseqc: A monoblock is made to switch on the so-called POSITION command of diseqc 1.0 (committed).
That means you can reach the two LNBs of a monoblock:
with commands A and B,
or with C and D,
or with A and D,
or with C and B.
Your diseqc commands must follow the actual, physical, setup that you have.


I hope I've explained better, this time?


greetz,
A33
Yes, I believe so. I will need a plain old T. When I program my reviever for the monoblock and whatever two ports I assign to each satellite. For example LNB1 port A and LNB2 port B. I have to make sure that my external diseqc is using the exact same ports for this to work?

Thank you
 
When I program my reviever for the monoblock and whatever two ports I assign to each satellite. For example LNB1 port A and LNB2 port B. I have to make sure that my external diseqc is using the exact same ports for this to work?

Well, yes. For instance with port A and B for the monoblock, choose port A and B of the diseqc switch.

[ However, if you for instance choose A and D in your receiver, and port A and D of your 4/1 switch, it works as well! That is because the 4/1 switch reacts to both the POSITION and the OPTION part of the command, but the monoblock itself reacts to only the POSITION part of the command.]

Greetz,
A33
 
The easiest way to do this, when you have still a free port on your 4/1 diseqc switch:
See the picture in this post: Due diseqc per un solo tuner
You would need a splitter or T-piece though; or solder a "bridge" inside the diseqc switch on the two output ports (the latter is the neater solution). I've had that working for years!
When your monoblock has two ports instead of one, it can also be done as in the picture in this post:

You could also use a diseqc 1.1 switch, or a special diseqc 1.0 OPTION switch. They are more expensive solutions...

Does this help?


Greetz,
A33


PS Do you want to read about it? This is the original thread: oplossing komb. monoblock/diseqC switch

Edit, PS2: Your receiver must issue a diseqc repeat for this above diseqc 1.0 solution to work. Most modern receivers do indeed repeat the diseqc commands....
Just want to thank this person and anyone who searches this topic. The above method work AOK.

Thank you.
 
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My KU FTA system is back online.

How accurate is Lyngsat today?