Hi Zak, You wrote: Although I like the idea of Ethernet to connect to and control a mount, I'm left trying to convince myself that it would be actually more useful than serial. I think it would be more useful than serial. Here's some reasons why: * Even at "only" 100 mbit speeds (1 Gbit is common and 10Gb emerging) Ethernet can theoretically transfer data 10,000x faster than the current serial port rate of 9600 baud... and with much lower overall latency than serial. What would this mean in practice? It would mean the entire state of the mount could be transmitted in a single packet with very little overhead and latency on either the mount controller and the computer. In fact the RA/Dec polling mechanism might not be needed at all if the mount were to anonymously broadcast or multicast it's state every second or so. Speaking from a developer's point of view having the entire state of the mount in a single packet would very much simplify applications that would use the protocol, including the ASCOM driver and APCC. Instead exchanging many packets to get the mount state it could be done with one packet and in just a few milliseconds. Because Ethernet is more than a point to point medium not only could your computer know the mount's position but theoretically an IPhone/IPad/Android application could monitor or control the mount. You might still have to have the controlling computer near to the mount because other devices have USB connections but you could have a second computer showing status or with the ability to make emergency stops or park the mount. * Ethernet connections, unlike serial and USB, can support multiple logical connections. This means if you do have multiple Ethernet devices at your mount (e.g. mount and camera) you still only need one cable leading away from the mount if you use a cheap ethernet hub at the mount. Some higher end CCD cameras have Ethernet ports. If you were to put a low-power wireless router at the telescope you could even go wireless to your laptop. After all, wouldn't a network port on the mount require some form of OS to be useful? Then once on the network,
how reliable and secure would this OS be, for example against attacks or simple user error? (I'm thinking a locked-
down Linux would probably do the trick). Real-time embedded operating systems have existed for a long time. In most cases these systems have read-only code so hackers can't just inject new code or applications into firmware. There are numerous ways to secure a telescope from abuse. For instance you could put an off the shelf router at the telescope or on the local LAN. These typically cost less than $100 and most have excellent defenses against attacks. The mount's firmware would then just need a basic security mechanism built into the protocol. An even higher security level could be implemented to allow the user to enter a single or range of authorized IP addresses. Command requests from other IP addresses would be rejected. I've actually implemented something similar to this in a product I once worked on. The second is an altogether grander (and riskier and costlier) affaire: A standalone, integrated remote controller.
This device would combine the mount controller electronics within a modular, ruggedized server that could also
host all the connectivity ports for accessories (i.e. USB and serial, as well as VGA for local / console access), an
update-able OS for the device drivers, and a robust suite of browser-based remote control software. The modules I could think of:
Core module : GTOCP
Remote control model : Ethernet port, webserver running APCC, ACP or equivalent.
Wifi / Bluetooth module : wireless access to LAN, close range remote control.
Accessory module : 4 USB ports, 4 serial, preloaded with range of drivers, maybe choice of OS depending on
driver availability
Storage module : 2/4/6 bay RAID, to store and host captured images before processing
UPS module: graceful shutdown during power outages Honestly, I don't think something this elaborate would be worthwhile. Only a handful of people and institutions might buy it. Besides this is essentially a PC. Remote users will probably still want to build/buy their own computer because it would likely be much cheaper and they could design it to exactly their needs. -Ray Gralak Author of Astro-Physics Command Center (APCC) Author of PEMPro: http://www.ccdware.comAuthor of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriverAuthor of PulseGuide: http://www.pulseguide.comAuthor of Sigma: http://www.gralak.com/sigma-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On Behalf Of zakky2k
Sent: Friday, October 19, 2012 3:54 AM
To: ap-gto@...
Subject: [ap-gto] Re: Why AP mount don't have a USB port?
While chewing on the idea about an ethernet controlled mount, I reached a very similar conclusion to Christopher,
namely a modular GTOCP with a range of extensions.
Although I like the idea of Ethernet to connect to and control a mount, I'm left trying to convince myself that it would be actually more useful than serial.
Sure, it would be simpler to attach the mount directly as a resource on either the local or wider network but a local
PC would still be required and at the cost of increasing the complexity of the controller.
After all, wouldn't a network port on the mount require some form of OS to be useful? Then once on the network,
how reliable and secure would this OS be, for example against attacks or simple user error? (I'm thinking a locked-
down Linux would probably do the trick).
Considering that remote control of a mount is already achieved through software running on a PC next to the
mount, unless AP want to get deeper in to the software business, or partner up with established providers, there
doesn't seem to be much room for improvement over the current situation.
Then there's the abundance of both serial and USB peripherals (cameras, filter wheels, focusers and rotators etc)
that make up an imaging platform. Some form of local PC is still required to provide power, connectivity and drivers
to these devices.
I submit to the group that two options are available: The first, as alluded to initially, would simply allow the mount to be accessed directly over the network using tcp/ip. Aside from the odd compatibility issue with certain serial to USB
adapters, would this make any difference from a user's perspective as a PC is still required locally for peripheral
and observatory control?
The second is an altogether grander (and riskier and costlier) affaire: A standalone, integrated remote controller.
This device would combine the mount controller electronics within a modular, ruggedized server that could also
host all the connectivity ports for accessories (i.e. USB and serial, as well as VGA for local / console access), an
update-able OS for the device drivers, and a robust suite of browser-based remote control software.
Sure, this approach has a barrage of problems (choice of OS vs driver support for example), but wouldn't it be a
dream come true for remote imagers?
I realise that this is already what people achieve using their own choice of software (e.g. ACP) and hardware, from
laptops for mobile observers, to desktop or even rack mounted servers for permanent installations.
Just imagine though, only power and network required at any observatory (even non-permanent), everything else
connected to one modular control box, designed, built and tested by AP specifically for their mounts but with the
possibility to extend its use for any peripheral via modules and combined with an internal web-server, running either
custom or OEM' d software for remote control through a browser or app from anywhere in the world.
The modules I could think of:
Core module : GTOCP
Remote control model : Ethernet port, webserver running APCC, ACP or equivalent.
Wifi / Bluetooth module : wireless access to LAN, close range remote control.
Accessory module : 4 USB ports, 4 serial, preloaded with range of drivers, maybe choice of OS depending on
driver availability
Storage module : 2/4/6 bay RAID, to store and host captured images before processing
UPS module: graceful shutdown during power outages
Obviously more aimed at the permanent installation, as casual users most likely would simple use a laptop and
achieve most of the above functions, but even for the casual observer, removing the headache of trail and error
with software and hardware compatibility, and replacing it with a box that just worked, would not doubt still be
appealing.
Just my thoughs...
Zak
--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> , "Christopher Erickson"
<christopher.k.erickson@...> wrote:
I would love to see a gradual migration to a modular interface socket, where
the user would have a choice of swappable interface modules, including:
RS-232 - Still the universal denominator
USB-HID - USB interface that wouldn't need drivers!
Ethernet/IPv4-IPv6 - Rock-solid, multi-device interface with unlimited
distance
Ethernet/IPv4-IPv6 with PoE - Ethernet with power, all in one connector
FTDI fiber-optic - All of the benefits of Ethernet with lightning and ESD
immunity!
WiFi - For iPhones, iPads and the WiFi'd observatory
Bluetooth - For Android phones, tablets and more
Xbee wireless - For the more-serious astro-geek robotic observatory
I2C - Fast & simple multi-device interface standard used between
microcontrollers
And of course more modules could come out in the future, as computer
interfaces evolve over time.
I would be thrilled if AP were to lead the way into the future with a
modular interface socket that would be available to other manufacturers as a
licensed or license-free standard.
Each module would be about 3/4" x 3/4" x 1.5" and would plug flush into a
matching socket on the mount's control box.
I think this would be a great boon to mounts, focusers, filter wheels,
optical manifolds, rotators, dome controllers and all other observatory
devices that have low data rate requirements. Cameras and such will always
need high-bandwidth interfaces that will follow the latest interface
standards and will always be at a greater risk of quick-obsolescence
accordingly. Anybody want a camera with a parallel or SCSI interface? I
got boxes of them.
Years ago I remember arguments from stubborn Apple Mac users about why
didn't GOTO mounts have SCSI-II interfaces. Sounded just like the arguments
for USB today.
Christopher Erickson
Consulting Engineer
Summit Kinetics
Waikoloa, HI 96738
www.summitkinetics.com
-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> [mailto:ap-gto@...
<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of
Daniel Marcus
Sent: Thursday, October 18, 2012 10:05 AM
To: AstroPhysics E-group
Subject: RE: [ap-gto] Why AP mount don't have a USB port?
Hi Anthony
my poor laptop only has one serial, 1parallel, 1 eithernet and 2 USB1
ports : (( Can't cram in the USB2 and extra serial adapters into the slots
at the same time as they will not fit. Really need a good way to control the
mounts, and supporting equipment easily. There should be a way to get -
camera, guide camera, mount, filter wheel, focusers (2) and possibly a
filter tuner and extra focuser and camera for those with Halpha scopes.
Never mind the roof or dome controls, weather inputs, and cameras to view
remote what is going on. That is a lot of stuff to get working all at once.
Be nice to have a hub to plug them all into at the mount and then send the
signals back via a single LONG cable to where your main computer is located.
With a big lightning arrestor protecting the whole thing! Need a good IT guy
to get it sorted out. I'm with AP though, I want a device that will not
become obsolete. I intend to own the mount for 20 to 30 years, and I want it
to run on Windows ver 45. Serial will be around for a LONG time, and mounts,
focusers and filterwheels do not need fast communications unlike cameras.
Have 2 PCI serial cards in the main obs computer, works just fine. Have more
troubles with the USB extender hub and drivers than I do with the serial
ports.
Either net would be nice if there was an easy way to assign all the stuff.
Daniel Marcus
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
From: ayiomami@...
Date: Thu, 18 Oct 2012 20:52:08 +0300
Subject: Re: [ap-gto] Why AP mount don't have a USB port?
Similar cards exist for USB2.0 for those of us whose laptops are
exclusively USB1.1. Some software and hardware, specifically requires USB2.
Anthony.
???? 10/18/2012 20:40, ?/? chris1011@... ??????:
You cannot put a PCMCIA card into your laptop? There's a place for one in my Dell laptop. Here's one for $29.00: http://www.usconverters.com/index.php?main_page=product_info&cPath=69&produc
ts_id=251
Rolando -----Original Message----- From: popkrab <popkrab@... <mailto:popkrab%40yahoo.com>> To: ap-gto <ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap- gto%40yahoogroups.com>>
Sent: Thu, Oct 18, 2012 12:33 pm Subject: [ap-gto] Why AP mount don't have a USB port? I have a Mach1GTO and it works very fine except when I do polar alignment routine by using star drift method. I use this mount for imaging by connecting the mount to my laptop computer. I would like to know why AP don't provide a USB port on CP3 controller box? What is a different between old fashion serial port and new USB 2.0 port? Because I have to buy a good quality USB2serial adapter. Sometime this adapter was fail during imaging session. If I can choose, I would preferred a USB connection than serial port. What are good points of serial over USB interface? Thank you very much. POP
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