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teixeiragv
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Access to a remote serial port

Tue Jan 20, 2009 12:06 am

I have roughly 30 Mikrotik p2p links (using RBs 433AH), where I need serial connections.
Some of those connections are over a single hop and others over multiple hops to a server.
I would like to connect (like) virtual tunnels to the serial ports, so it can send and receive data between 2 serial ports on the RBs.
Also, I would like to be able to connect a hyperterminal session to a remote device connected to the RB 433AH's serial port.

Mikrotik,
I believe you will enter in a new zone of applications by having this feature. I know innumerous applications where companies are paying 5 to 10 times more for a single low speed link just to have a serial connection.

Thanks
 
changeip
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Re: Access to a remote serial port

Tue Jan 20, 2009 12:37 am

you can already do this, check the last newsletter i believe. they implemented the rfc for that finally : )
 
cmit
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Re: Access to a remote serial port

Tue Jan 20, 2009 12:08 pm

Depending on what you really want to achieve, you can select from

a) "/special-login": Using this you can login via telnet/ssh to the router and transparently access the serial port. We use this to access VDSL equipment behind a MikroTik, for example.

b) "/port remote-access": This lets you access the serial port over TCP using something called a "virtual serial port" or similar. I.e. you install appropriate software on you PC, and access the device connected to the MikroTik as if it were connected directly to a COM port of your PC. This feature is implemented according to RFC2217.
Appropriate software could be from Eterlogic (here: http://www.eterlogic.com/Products.VSPE.html) - this is freeware even for commercial use. Setup might be not absolutely intuitive for this purpose, as you have to configure two virtual ports here...

If you need more assistance, just ask ;-)
 
cmit
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Re: Access to a remote serial port

Tue Jan 20, 2009 6:01 pm

As this question comes popping up again and again, I put up a wiki article about serial port redirection in RouterOS: http://wiki.mikrotik.com/wiki/Serial_Port_Usage
 
cmit
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Re: Access to a remote serial port

Tue Jan 20, 2009 6:03 pm

And to the original poster (teixeiragv):
I don't think you can connect together the serial ports of two RouterOS devices to create a "long, networked null-modem cable". At least not without using a separate server...
 
teixeiragv
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Re: Access to a remote serial port

Tue Jan 20, 2009 11:45 pm

Was thinking to create a virtual tunnel with high QOS to dedicate some bandwith and associate the serial ports to a bridges on both sides.
Have not tried yet... Will... ...later tonight.
I am installing a solar power regulator up the top of the hill tomorrow and need to monitor the consumption of the site through the serial port.

Cmit, can you please help me? How can I get this running with separate servers?

Thanks
 
cmit
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Re: Access to a remote serial port

Wed Jan 21, 2009 1:13 pm

teixeiragv,
could you send me a short reminder to info (a) cmit (dot) de?
 
teixeiragv
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Re: Access to a remote serial port

Thu Jan 22, 2009 1:02 am

Hi,
Thanks cmit!! Yeah! I can access the serial0 from any PC (with Virtual Serial port Emulator installed) on the network.
I can successfully hyperterminal to a Relay connected to the serial port on a remote RB433AH.
The problem I am facing now is that the solar power regulator turns its serial port on, only if the RB433AH sets serial0 pin 4 (DTR) hi and pin 7 (RTS) low.
At the regulator I can connect pin 7 and 5 (GND) together.... but pin 4 of serial0 needs to go hi just when the Solar power monitor application is running on my PC... I don't want to leave an extra 5Volts draining the batteries 24/7 up the hill!!!
It comes the question them.... Is there any way to set pin 4 - DTR hi when the RB433 sees a connection to the TCP port 10000 and set pin 4 low when the TCP 10000 is NOT connected to anything?

Thanks again!
 
cmit
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Re: Access to a remote serial port

Thu Jan 22, 2009 2:14 pm

I don't think so, as RouterBoards do not have DTR and the other "extra" serial signal pins. This is (if I recall correctly) a hardware limitation by the chipset or so.

Missed this heavily when trying to connect a weather station over a MikroTik, too :-(
 
teixeiragv
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Re: Access to a remote serial port

Fri Jan 23, 2009 12:26 am

What about the /tool sigwatch? It says we can monitor the dtr, rts, cts, dcd, ri and dsr pins. I would understand that the hardware has them all.

http://www.mikrotik.com/testdocs/ros/2. ... gwatch.php
 
soleed
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Re: Access to a remote serial port

Mon Feb 02, 2009 2:24 pm

can we send a pulse command from serial port ? i just need a script can send pulse on serial
 
sten
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Re: Access to a remote serial port

Mon Feb 23, 2009 12:20 pm

Have you tried;

/ port set serial0 dtr=on rts=off

or something similar?
 
rmichael
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Re: Access to a remote serial port

Thu Oct 01, 2009 1:47 am

This is an overkill, but if anythig else fails you could use this Watch Dog Timer:
http://www.industrologic.com/uwdtman.htm

and wire it so when it detects TX/RX activity it pulls #4 high via relay...

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