[SOLVED] Connecting 2 devices 150m apart.

I have to connect 2 devices, in two different buildings which are 150m apart atleast. I tried connecting these two devices through a LAN cable, but I had no connectivity. Later I understood the limitations of LAN cable (max length.100m).

I want to know if I can connect these two devices without using any LAN repeaters (I did not find in the market)?
I have Internet connectivity in both the buildings. Is there any way I can connect to the other device using the Internet?
If there are any other means of connecting them please share your views.

Appreciate your help.


BugsBunnyBoss

Depending on the switch/router hardware and the availability of plugin modules, there are gigabit multi-mode fiber standards which offer a maximum run length of 220 to 550 meters.

There are also gigabit single-mode fiber standards which offer maximum run lengths of 5km to 70km.

You could implement a VPN through the internet cloud, however many Internet connections are asymmetrical, the upstream speeds are often a fraction of the downstream speed.

There are also several wireless options which would exceed the throughput of a VPN connection.

BigDog

Thanks BigDog. The gigabit fiber seems to be an easy fix. Could you please direct me to some source; for reading more about these devices? Any particular device you have in mind?

Hi,

A simple LAN cable should work for simple UART style data transfer.
Use Rs422/Rs485 differential signals and the terminating resistors.

No transformer, no lan repeater, no other active device. Connect the shielding of the cable to each device's GND.

Klaus

As I mentioned, depending on the switch/router gear, there are plugin or SFP, XFP, GBIC, MIA transceiver modules available for various switches or routers.

Most commercial grade switches, Cisco, Netgear, etc, have SFP, GBIC, etc, slots available for optical transceivers.

For example:



Most of these transceivers are available used on eBay at significant savings, as well as terminated fiber optic cable.

What type of network equipment do you have currently installed in these buildings?

BigDog

bigdogguru said:

What type of network equipment do you have currently installed in these buildings?
BigDog

Click to expand...

Its a small home office scenario. So no big equipment's. In my home I have a Desktop-PC and TP-link WR1043ND modem router. and in my office, which is about 150m away, I have the attendance machine which has a LAN port, and the same router TP-link WR1043ND. I also have D-link 16 port switch in my office.

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KlausST said:

Hi,

A simple LAN cable should work for simple UART style data transfer.
Use Rs422/Rs485 differential signals and the terminating resistors.

No transformer, no lan repeater, no other active device. Connect the shielding of the cable to each device's GND.

Klaus

Click to expand...

My attendance device don't have a RS422/485 port.

100 m ethernet cable segment length is valid for 10BASE-T and unshielded twisted pair (standard 0.5 mm telephone cable). I would expect that higher quality cable works for 150 m, at least if you restrict the speed to 10 Mbit/s. If it doesn't work, there are converters to other physical layers working on twisted pair media available. Fiber would be the utimate solution, as already suggested.

Hi,

I totally misunderstod the problem...

Klaus

bugsbunnyboss said:

Its a small home office scenario. So no big equipment's. In my home I have a Desktop-PC and TP-link WR1043ND modem router. and in my office, which is about 150m away, I have the attendance machine which has a LAN port, and the same router TP-link WR1043ND. I also have D-link 16 port switch in my office.

Click to expand...

I actually have a similar situation, I have a two story building which is an office/workshop at one end of my property, along with my personal office in the main house at the other end, although in my case both sites represent a distinct network consisting several workstations and servers.

You have several options, all of which would require a commitment of time and money.

As FvM indicated, a similar connection maybe possible with a higher quality run of copper cable, operating at lower speeds.

However, considering the current pricing of such appropriate cabling and my past experiences with long runs of copper either buried or in conduit, my recommendation would be to utilize fiber.

Probably the most bang for your buck would be to purchase two used 10/100 switches with either GBIC or SFP ports, like the following:

eBay - NETGEAR ProSafe 24 Port 10/100 Managed Switch w/ 2 GBIC Ports FSM726 v2

Then find two identical optical modules compatible with the switches and a compatible terminated fiber optic cable, both of which are available on eBay.

With careful planning and shopping you may be able to implement the network connection in the $100 to $200 range.

The good new is once the network is configured, you should be able to alleviate one of the internet connections and its monthly fee.

Also with switches located at both sites, you would be able to readily add workstations, network printers, etc at either site and share these resources across your network.


BigDog

bigdogguru said:

As FvM indicated, a similar connection maybe possible with a higher quality run of copper cable, operating at lower speeds.

However, considering the current pricing of such appropriate cabling and my past experiences with long runs of copper either buried or in conduit, my recommendation would be to utilize fiber.

Probably the most bang for your buck would be to purchase two used 10/100 switches with either GBIC or SFP ports, like the following:

Then find two identical optical modules compatible with the switches and a compatible terminated fiber optic cable, both of which are available on eBay.

With careful planning and shopping you may be able to implement the network connection in the $100 to $200 range.

The good new is once the network is configured, you should be able to alleviate one of the internet connections and its monthly fee.


BigDog

Click to expand...

I already found two switches. Now I only have to buy the optical modules and its compatible fiber optic cable. I plan to buy them this weekend.

Though I have the option of sharing the Internet connection, I'd prefer to have separate connections.

@FvM - I used 155m of a cat6 cable for the connection. yet I had no connectivity. Any idea why? Finally, is it possible to manually control the speed of a LAN?

There's a problem with 100 MBit endpoints that they negotiate the connection speed at 10 MBit. If both signal 100 MBit capability, they switch to 100 MBit, possibly starting an endless loop when the 100 MBit transmission fails. The solution is to restrict one peer to 10 MBit, that's e.g. possible in the ethernet interface registry settings of a Windows PC, but usually not for switches.

bugsbunnyboss said:

I have to connect 2 devices, in two different buildings which are 150m apart atleast. I tried connecting these two devices through a LAN cable, but I had no connectivity. Later I understood the limitations of LAN cable (max length.100m).

Click to expand...

You can also check out VDSL. There are VDSL routers you can connect back-to-back. The connection between routers can be standard phone cable, but in your case, use that LAN cable. I have 250m phone pair cable and two Zyxel Prestige 841 routers, works fine. ftp://ftp.zyxel.com/P-841/datasheet/P-841_1.pdf.

Before ordering routers please verify that you can configure one as central and other as client. For example P841 has two different types P841 as client and P841C as central.

FvM said:

The solution is to restrict one peer to 10 MBit, that's e.g. possible in the ethernet interface registry settings of a Windows PC, but usually not for switches.

Click to expand...

Typically managed switches offer the ability to set the maximum port speed, at least both the Cisco and Netgear managed gigabit switches I currently have running offer this feature.

@bugsbunnyboss

Utilizing 10/100 Mb switches is certainly the least expense option. At least, if some time in the future you require gigabit speeds, you will already have a 2 to 4 gigabit trunk in place so that you will only need to replace the switches with models which support gigabit speeds.

Please Note:

Keeping both internet connections will complicate the network configuration a bit, as the network will have two gateways, two separate routes, two DHCP servers, etc.

While it is certainly possible to properly configure your network for this scenario, when testing the connection between the two sites, ensure to power down one of the routers.

In fact, it might account for issues when testing the CAT6 connection you described in your previous posts.

BigDog

bigdogguru said:

In fact, it might account for issues when testing the CAT6 connection you described in your previous posts.
BigDog

Click to expand...

I connected the attendance device directly to my home network switch(Gb). So the router in the office could not have influenced anything. I'm guessing the speed should have been 100Mb/s. and that's the reason cat6 cable did not work.

I came across media converters($50) with optical fiber cable. I think it is a good solution; given that I have to connect the attendance device only to my home network.

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TommiRouvali said:

You can also check out VDSL. There are VDSL routers you can connect back-to-back. The connection between routers can be standard phone cable, but in your case, use that LAN cable. I have 250m phone pair cable and two Zyxel Prestige 841 routers, works fine. ftp://ftp.zyxel.com/P-841/datasheet/P-841_1.pdf.

Before ordering routers please verify that you can configure one as central and other as client. For example P841 has two different types P841 as client and P841C as central.

Click to expand...

I tried looking for that device in e-bay, but it costs more than $50 inclusive of shipping.