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Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

by ian＠platinum.net

On 2013-01-17, at 11:00 PM, Dave McGuire <mcguire at neurotica.com> wrote: What sort of hardware interface would you envision? Two ports - Sync and Ethernet. Maybe a couple of status LEDs. What do we need for config? Local IP address, Remote IP address, Baud rate (because we'd need to generate clock if I'm not mistaken). How do we get parameters in? Web interface or telnet CLI ? Maybe DHCP extra parameters (no need to write a GUI, but some people will find configuring their DHCP server to serve additional parameters very difficult). UDP means not having to worry about master and slave. Your thoughts? Ian

12 years, 3 months

Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

by mcguire＠neurotica.com

On 01/18/2013 01:37 AM, Ian McLaughlin wrote: I'd do it with an HDLC/SDLC-capable chip like a Z8530...offload as much from the firmware as possible, leave those cycles for protocol handling. Unless you meant wrapping bare ?DLC frames in packets? I was thinking that we don't even need to decapsulate the serial frame at all - just detect the start and end. All we're doing is emulating a piece of wire, after all. Unless we're putting in a fancy LCD status display, but I think that's overkill. Ohhhh ok, that's an interesting idea; make it a "dumb" transparent bridge. I was thinking we could do interesting translational stuff at the protocol level, but one can't beat the utility of a dumb get-bits-from-here-to-there bridge. I like this idea! I have that problem as well, but I got really excited when you mentioned it, because I am doing a lot of designs with Ethernet now. I have a "base" design, a "hardware macro" if you will, that I've recycled several times. It's a Philips..erm, NXP LPC2300-series ARM7 with an on-chip Ethernet MAC, and all supporting hardware. I typically run FreeRTOS and uIP on them. The only things I have dev platforms are on my end are PIC and Atmel. I do a lot of AVR stuff for work, but mostly that's maintenance of previous controllers. All of our current stuff (and my personal stuff) is ARM7 now. If (and I'm not pushing, or even suggesting!) you ever want to get into it, I can give you a big head start. I have some Zilog stuff, but I gave up on them several years ago. Same here...after a significant investment in time, code, and blank PCBs. Their management is incredibly, unbelievably bad. I used the eZ80F91 in several commercial products. Great chip. Crappy tools. Crappy company management. However, if you're able to put together the hardware layer, and there's a C compiler available for your platform, I can help on the software side. I've also done some software work for a local company that uses a TI Davinci processor. I am, and there is, that would be great, and...wow that's cool! :-) What sort of hardware interface would you envision? Interfacing an ?DLC engine to that would be a cakewalk starting from that base design as a head-start. I have a few tubes of Z8530s in PLCC-44 packages here. Oh oh. I think there's another project starting... :) Oh there are just too many. ;) -Dave -- Dave McGuire, AK4HZ New Kensington, PA

12 years, 3 months

Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

by ian＠platinum.net

On 2013-01-17, at 10:48 PM, John Wilson <wilson at dbit.com> wrote: Careful -- UDP doesn't guarantee in-order delivery. How does HDLC feel about little surprises? HDLC information and supervisory frames have sequence numbers. There's also unnumbered frames used for control purposes. The commercial units I found used UDP as their ethernet transport. Ian

12 years, 3 months

Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

by mcguire＠neurotica.com

On 01/18/2013 01:48 AM, John Wilson wrote: I'd do it with an HDLC/SDLC-capable chip like a Z8530...offload as much from the firmware as possible, leave those cycles for protocol handling. FWIW, I'm in the middle of writing a Z8530 driver for E11 (in heavily commented x86 code), which I'd be happy to contribute (after modifying as needed) if you aren't already neck-deep in SCC code. I built a Z8530-based AX.25 PAD for ham packet radio...but that was 25 years ago! I remember being thoroughly impressed with the Z8530, and I've used it in several projects since then...but only in async mode. So yes...if you're doing sync stuff with it, that might be very handy if we do this and it goes this route. We could certainly do the framer in firmware; there's a certain appeal to that...but I'm a big fan of distributed processing, and as the iOS device saying goes, "there's a chip for that". Wrapping the data in UDP is simple. The HDLC layer could deal with error detection/correction. Yes! Careful -- UDP doesn't guarantee in-order delivery. How does HDLC feel about little surprises? I would imagine it'd be offended. ;) However if memory serves, HDLC frames contain a few bits' worth of sequence numbers. These could be checked and buffered/re-issued to recover from most bad situations, I would think. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

12 years, 3 months

Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

by wilson＠dbit.com

From: Dave McGuire <mcguire at neurotica.com> I'd do it with an HDLC/SDLC-capable chip like a Z8530...offload as much from the firmware as possible, leave those cycles for protocol handling. FWIW, I'm in the middle of writing a Z8530 driver for E11 (in heavily commented x86 code), which I'd be happy to contribute (after modifying as needed) if you aren't already neck-deep in SCC code. Wrapping the data in UDP is simple. The HDLC layer could deal with error detection/correction. Yes! Careful -- UDP doesn't guarantee in-order delivery. How does HDLC feel about little surprises? John Wilson D Bit

12 years, 3 months

Sample DCL code for simple client-server task-to-task comms

by sampsa＠mac.com

Think of this as a notification system and text message extension to VMS PHONE :) PHONE HELP MAIL ? That doesn't give you an overview of everybody logged on anywhere, an IM system does. This is more of a system to see who's online rather than to necessarily communicate with them, PHONE etc are much better, which is why I should where the "buddy" is logged in. Sampsa

12 years, 3 months

IBM bisync on Ciscos (off-topic)

by mcguire＠neurotica.com

This is way off-topic so I will be brief. Does anyone here know if it's possible to connect an IBM bisync device (like the host interface on a 3174-61R) to a serial interface on a Cisco router, and talk it into bridging to Ethernet in whatever protocol(s) the Ethernet-attached 3174s speak? Thanks, -Dave -- Dave McGuire, AK4HZ New Kensington, PA

12 years, 3 months

Sample DCL code for simple client-server task-to-task comms

by sampsa＠mac.com

Half a year or maybe a year ago. Sampsa was running a program which used PHONE to check who was logged in on various machines. When he tried all machines in area 1, MIM got loads of entries in the log for Sampsa's machine trying to talk with machines that were down. (I might be remembering things wrong, and I might be mixing things up, but it was not as if MIM crashed or anything because of Sampsa's code, but I asked him to stop, as he was filling up plenty of logs as far as I can remember.) Yeah, I didn't mean crashed MIM or anything, but caused problems - basically the phone directory just went through the nodelist and did a PHONE DIR to them..If a node was down, the call would fail. It wasn't a good idea from BQT's side :)

12 years, 3 months

Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

by ian＠platinum.net

On 2013-01-17, at 10:20 PM, Dave McGuire <mcguire at neurotica.com> wrote: I'd do it with an HDLC/SDLC-capable chip like a Z8530...offload as much from the firmware as possible, leave those cycles for protocol handling. Unless you meant wrapping bare ?DLC frames in packets? I was thinking that we don't even need to decapsulate the serial frame at all - just detect the start and end. All we're doing is emulating a piece of wire, after all. Unless we're putting in a fancy LCD status display, but I think that's overkill. Wrapping the data in UDP is simple. The HDLC layer could deal with error detection/correction. Yes! The problem is finding surplus time to embark on this. Maybe a few of us could collaborate on it? I have that problem as well, but I got really excited when you mentioned it, because I am doing a lot of designs with Ethernet now. I have a "base" design, a "hardware macro" if you will, that I've recycled several times. It's a Philips..erm, NXP LPC2300-series ARM7 with an on-chip Ethernet MAC, and all supporting hardware. I typically run FreeRTOS and uIP on them. The only things I have dev platforms are on my end are PIC and Atmel. I have some Zilog stuff, but I gave up on them several years ago. However, if you're able to put together the hardware layer, and there's a C compiler available for your platform, I can help on the software side. I've also done some software work for a local company that uses a TI Davinci processor. Interfacing an ?DLC engine to that would be a cakewalk starting from that base design as a head-start. I have a few tubes of Z8530s in PLCC-44 packages here. Oh oh. I think there's another project starting... :) -Dave -- Dave McGuire, AK4HZ New Kensington, PA --- Filter service subscribers can train this email as spam or not-spam here: http://my.email-as.net/spamham/cgi-bin/learn.pl?messageid=410C8376613711E2A…

12 years, 3 months

Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

by mcguire＠neurotica.com

On 01/18/2013 01:14 AM, Ian McLaughlin wrote: I'm not working on anything now - I just came up with the idea. I meant "do you design stuff with microcontrollers". I did some Googling, and there seems to be commercial units, all around $1K per end (async is much cheaper). Good heavens! Microcontrollers and digital electronics is another one of my hobbies. Excellent! Same here, though I also do it professionally. Async serial is simple for a microcontroller to handle. I've never actually looked to see if there's any synchronous libraries out there. I'd do it with an HDLC/SDLC-capable chip like a Z8530...offload as much from the firmware as possible, leave those cycles for protocol handling. Unless you meant wrapping bare ?DLC frames in packets? Wrapping the data in UDP is simple. The HDLC layer could deal with error detection/correction. Yes! The problem is finding surplus time to embark on this. Maybe a few of us could collaborate on it? I have that problem as well, but I got really excited when you mentioned it, because I am doing a lot of designs with Ethernet now. I have a "base" design, a "hardware macro" if you will, that I've recycled several times. It's a Philips..erm, NXP LPC2300-series ARM7 with an on-chip Ethernet MAC, and all supporting hardware. I typically run FreeRTOS and uIP on them. Interfacing an ?DLC engine to that would be a cakewalk starting from that base design as a head-start. I have a few tubes of Z8530s in PLCC-44 packages here. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

12 years, 3 months

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