Re: Taking the red pill...

new topic     » goto parent     » topic index » view thread      » older message » newer message
katsmeow said...
ghaberek said...

The second device is the actual Ethernet device which you would command and control via its proprietary serial (text-based) protocol. Their website has a PDF describing this: http://www.hi-flying.com/eport-e20 (see "Software Funtion" [sic] document).

Like https://www.ebay.com/itm/253522532645 ?

The first eBay item you posted was this one: https://www.ebay.com/itm/353453817112 and the label on that device says "Eport-E20" so that's what I googled and to find the link I provided: http://www.hi-flying.com/eport-e20. This one you just posted now is: https://www.ebay.com/itm/253522532645 and that label says "Eport Pro-E20" which I found here: http://www.hi-flying.com/eport-pro-ep20.

katsmeow said...

The description is it's for linux networks. And uses a MIPS MCU , and says i must "Use FreeRTOS Operation System" on it.

It's all from Chinese manufacturers so most of it's in Engrish and has to be deciphered. The devices that say "FreeRTOS" are running that directly on the microcontroller. The ones that say "Linux" look like they're running OpenWRT which is a tiny Linux operating system for network devices. Neither of these seem to require knowledge of the actual operating system per se. Most of the configuration is done via a web or telnet interface, or directly via a serial console (like PuTTY).

katsmeow said...

As i know no linux, MIPS, or FreeRTOS, this sets me back to about 1994 on the learning curve, and it's not worth it, especially as that doesn't include the learning curve for OE on linux, or buying a new desktop computer to run the linux on.

I don't think you need to know any of those things to work with one of these devices. But you would need a compatible RS-485/RS-422 serial port, which is not included on typical PCs as those use RS-232 if they even do have a serial port at all. That 2 in 1 USB to RS422 to RS485 Converter you posted should work. Then you'd need to wire the pins for RS-485 to the Ethernet device and then you should be able to send serial commands to the device to make it do things.

I'm curious what your end goal is here. If you're hooking this all up to a PC then at the end of the day you're just building a really slow network adapter that works over serial, which a simple $5 USB network adapter would provide at a fraction of the cost and complexity and a hundred times the speed. These kinds of devices are meant to be attached to or embedded into dedicated real-world widgets that need network connectivity.

Regarding my experience with these things, at my job we work with a lot of devices, like roadside vehicle detectors, that are basic RS-485 serial devices. So we use these types of adapters to make them available over the network where the state's traffic management software can then interface with them directly. In these cases, the adapters are running in a "serial port server" mode where you can send serial commands over TCP and the adapter just relays the content back-and-forth between network and serial. The only thing we ever have to do directly on the device is program the IP address to get it online. We typically Wavetronix devices which are big and expensive but they're meant for long-term use in severe outdoor conditions. Those devices on eBay are just the stripped-down guts of these bigger devices.

-Greg

new topic     » goto parent     » topic index » view thread      » older message » newer message

Search



Quick Links

User menu

Not signed in.

Misc Menu