Callnet Systems

FAQ page

Is the Calnet 761 RTU still available?
Yes, Callnet Systems provides the RTU plus the 761 SG, 510 LG (Line Guard) as well as other Telco or Data Products.

I need just a circuit pack, not the mount (or housing). When looking at the products page why is there 4 different versions of both the RTU and SG5 ?
Since some customers want to use the circuit pack in different locations and since the switches and LEDs have to be built to face the user in each application we must know the application. Most customer have their own 400 shelf (L35). So in that case the RTU circuit pack that you would need would be 761RTU-L35. The SG part number would be 761SG5-L35 for that same 400 shelf.

We already have several RTU and SG5 products and would like to order more but we don't know what type mount or shelf we have used in the past ?
Use the L32 for the MDF, L33 for table top, L34 for 3-slot 1u and L35 for 11-slot 400 shelf 19" or 23" (most popular). Click here to see pictures of the four types of mounts. To summarize, if mounts are required you must order them seperately. If only a circuit pack is needed you still must provide the suffix to show where the circuit pack will be inserted.

Is the Calnet 761 RA still available?
No, but Callnet Systems does produce the 761RTU which provides the same Remote Access to Dial-Tone for test calls. The 761RTU is the new version of the older RA. The newer RTU is however not mounted in the older MDF block but rather a new MDF enclosure. This new L32 enclosure will mount in a standard MDF block space either horizontally or vertically. So if replacing the older RA you must also request both the 761RTU plus the 761L32 enclosure. (Note, the RA was actually used for both remote testing plus remote control through contact closures. We recommend not using the RTU for remote control unless there is a clear understanding of the low contact closure current limits)

Is the Calnet 761 SG still available?
Yes, Callnet Systems has re-designed and enhanced the 761SG.

What type of shelf should I put the 761 RTU or SG in?
It depends on where the unit will be located. If mounted on the Telco's MDF then the L32B mount should be ordered. If mounted in a 19 or 23-inch rack then order the L34 3-slot 2u 19" shelf.

What type power supply is required for the 761 Remote Test Unit, or the 761 Security Guard?
Normally 48 VDC power should be provided. In rare occasions other voltages such as 24VDC can be provided for special builds.

Is the Alertgate product powered by 48 VDC?
Typically the Alertgate product is powered by 120 VAC. Since Alertgate is made up of a standard PC platform running Callnet Systems Alertgate Sotfware, the end product could also be easily modified to have a 48V power supply.

Does Callnet provide a device that sends tracer locator tone out on cable pairs?
Yes, the 510 LG (Line Guard) product does just that. It can provide up to 5 tracer tone sources that are typically wired up to jacks on the MDF for rapid access to technicians.

How does the 510 LG provide a Combination of Tracer Tone plus Dial Tone?
A normal test line is wired to the LG as CO side Dial Tone. The output of the LG is then typically wired to a test jack on the MDF. Tracer Tone is normally sent out to the test jack and can be detected with a normal tone detector in the field. When the technician goes Off Hook and causes loop current, the LG will then remove the Tracer Tone and pass through the test Dial Tone. The technician can then make a normal voice test call without the Tracer Tone being heard. Going back On Hook will cause the Tracer Tone to once again be sent out the cable pair. The test line is typically called Combo-Tone by the Telco technicians.

Can the 510 LG send tone out on special circuit cable pairs?
Yes and no. Most all special circuits can be opened up and Combo-Tone applied since these are typically single pairs all the way out to the customer's premise. For Conventional 4-wire T1's, there can be a problem in passing the tone through T1 repeaters in the field. Newer 2 wire T1's although can still be identified using the 510 LG. A rule of thumb is, if the pair goes through a field repeater then the field repeater will probably not be able to pass the tone. See the next FAQ question in reference to Callnet Systems developing the worlds first device to send Analog Tone through Digitial Repeaters.

What can be done to pass Tone through a Conventional T1 field repeater?
Callnet Systems is presently developing a new LG that will allow analog tone through a 4 wire digital T1 on both Tx and Rx pairs. Check back for an announcement in the near future as development nears completion.

Is there a way to send normal dialup data over the internet without using a modem?
Yes, Callnet Systems is presently capable of doing this through a proprietary method. We can now send data across the internet to a special Callnet device that will convert it back to normal RS-232 signaling at the remote legacy device.

When sending data across the internet rather than dial up isn't there the possibility of a"man in the middle" monitoring the data we are sending and or receiving ?
Yes with other non-secure methods. However if you are using Callnet's Secure Messaging device the answer would be NO. The RS-232 data that is passed across the internet will be encrypted so that no one can monitor or capture it. It will be as secure as online banking.

For further information in reference to any of Callnet Systems' products see our Contact page and we will be glad to assist in the selection of the desired products.

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