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Need to connect 10 RS-232 lines to a Cobra II


#1

Can anyone suggest how to do this? Know of any hardware ?

I am thinking of using the USB host in the Cobra II and connecting that to a USB hub, then plug in USB-to-Serial cables from suppliers such as BlackBox.com or BB-elec.com. Your USB Host document here says:

https://www.ghielectronics.com/docs/36/usb-host

“There are many companies that create chips that convert USB to serial. GHI supports chipsets from FTDI, Silabs and Prolific. There is also a standard USB class defined for serial communication called CDC (Communication Device Class). This class is supported as well.”

Can anyone tell me where to get USB to serial adapters that use the chips mentioned?


#2

lots of the standard ones you’ll lbuy have Prolific, SiLabs, or FTDI chips. I’ve had mixed experiences with some USB-RS232 cables based on Prolific, but that’s just my personal feeling.

Here’s a question. 10 ? How much data are you talking about transferring and capturing/acting on? 10 sharing a single USB host connection may be a bad idea if you’ve got high latency sensitivity or high throughput requirements.


#3

What’s the baud rate of each RS232 connection?

I know I should not advertise other manufacturers here, but if you really need that many ports and want a single point hardware solution, then have a look at the MOD5234 from Netburner. You’ll easily get 10 ports with that. 8 will be on the eTPU and the other 2 are native. I ran all 10 before at 38400 with no issues or loss of data. This was the hardware I used before I moved to GHI modules. :slight_smile:

Your USB idea may have issues with timing as USB serial tend to have latency issues. It all depends on the baud rates you intend to use.


#4

there is also the question if MF will allow 10 USBH devices.


#5

Might take a look at ethernet serial converts. I use to use them at work ofr realtime industrial applications.

Lantronix
http://www.lantronix.com/device-networking/external-device-servers/

RocketPort (DeviceMaster)

It is as simple as opening a socket to the device’s IP and the port assigned to the comport. Some can even do 422 and 485


#6

Another option I just thought of. The SPI UART devices from Maxim might just work.