MC1000 Deskset 4 Wire Config

[pluto1914]

I am looking at getting a MC1000 but I need it to do 4 wire as that is how our building is setup.

I see in their documentation that it can be done. I'm looking to see what is needed to accomplish this and if anyone has done this type of install.

Thanks.

David

[wavetar]

Not sure what you mean by "how our building is set up". If they have 4-wire (or even 8 wire) jacks for connection, you only need to use 2 of the pins for your remote connection. Unless you mean there are already other 4 wire remotes installed & working in the building?

I guess we need a little more info...what type of radio are you ultimately connecting to, and do you have a TRA (tone remote adaptor) currently in place? If so, what make/model do you have?

[pluto1914]

Sorry...it was late when I typed that post. We have two Zetron 4010 consoles paralleled connected to an XTS5000 via local control (4 wire). We used to run tone remote to an old Kenwood, but when we switched to the XTS we lost the functionality and lost our tone remote handset on the 2nd floor. I see that the MC1000 is capable of local control via 4 wire and I wanted to see how I could integrate it with our current configuration.

David

[d119]

From the MC1000 Manual:

Programming Interface:

0000 = Two Wires
0001 = Four Wires
0010 = Four Wires - Duplex
0011 = Four Wires - Full Duplex

Programming is accomplished using the buttons & LED's on the front of the MC1000.

So yes, this is a dual-mode 2W/4W capable remote.

[pluto1914]

Is there any additional equipment needed to connect it via four wire?

[d119]

Nope. You just program it for what you want it to do.

Make sure you purchase the Tone or DC version depending on your needs.

[pluto1914]

Ok, I was looking at the documentation from Motorola. See th below URL and they mention a junction box for local control.

http://www.motorola.com/web/Business/Pr ... _5_New.pdf

David

[d119]

Well I would think Local Control would require more than 4 wires... TX+ RX+ TX- RX- PTT... That would essentially be E&M which is a 6-wire configuration.

Maybe I'm wrong, I don't know. 4-wire generally refers to tone remote control with duplex operation (one way on one pair, the other way on the other pair) so you can hear mobile units when they interrupt the dispatcher, so you can hear trunked call tones (talk permit/busy/no service), etc.

[Bill_G]

The j box shown in the Moto literature is a convenient termination point for multiple local control desksets into a single radio. In the past a j box was essentially a nice box with a labeled barrier strip inside and no active parts. You tied all your wires down inside, and it made a neat, professional looking installation. The DDN6337 described in the MC2500 series data sheet takes the concept a bit further by terminating in standard RJ45 connectors allowing you to use very common CAT5 ethernet cables, and increasingly available structured wiring to connect your radio to your desksets distributed around a building. Again, very nice and neat, very professional looking, but not absolutely necessary in an installation. A technician should be capable of connecting an XTL to a single local control deskset without a j box.



That said, I think some definition of terms is required by what I have read so far. There is a difference between local, tone, and dc control, and they do not mix well. A Local control is a microphone and a speaker on a long wire. The physical distance used to be limited to 100ft, but these days you can have about 1000ft of wire. You have to have a wire for every signal. The basic signals are: ground, PTT, mic hi, rx hi, and monitor. Depending on your radio system, and the model of radio you are using as a base station, you may or may not need monitor, you may need two wires for the receive, and another pair for the transmit audio. So, you may be able to use as few as 4 wires, or you may need as many as 7. You generally do not have channel change, scan on/off, or any advanced capabilities with a Local control. It is your basic push-to-talk, let-go-to-listen remote control with a convenient receive volume knob which is perfect for most people. You can put a few of these around the office without too many worries. Local control is the simplest type of remote, it is the easiest to understand, and generally connects to any mobile without any additional interface boxes required.

Tone and DC control is for extended distances when you exceed 1000ft. They are intended for use over dedicated circuits from the phone company though they can be used locally over in house wiring, and never extend into the phone company. They can be local to the radio, but that doesn't make them local controls which is a point of confusion for many people. Both tone and dc control require an adaptor box connected to the radio, or a wireline card built into the radio to decode the commands from the remote. Tone control, as the name implies, uses tone sequences to control the radio, and dc uses high voltage - low current to control it. DC is not commonly used anymore, and is offered as legacy support for older systems that do employ it. The phone company generally will not give you a circuit capable of dc control because it requires removal of their line conditioning and protections to provide a dry copper loop all the way from a control point to the base station which is dangerous for their equipment and personnel.

Tone control is the preferred method if you must transport through the phone company, or through your agency's microwave system since it is purely audio. It comes in either 2 wire or 4 wire configuration. 2 wire puts transmit and receive audio on the same pair, and 4 wire puts them on separate pairs. That is another point of confusion for people. The installer may have used a cable with four wires in it, but that doesn't automatically mean it is a 4 wire circuit. In general, you use 2 wire circuits when you have more than one control point (ie: many remote controls spread around the facility) so all desksets can hear both sides of the conversation. There would be no point in building a 4 wire circuit, and then cross connecting the transmit and receive pairs so everybody could hear everybody else. It defeats the purpose of using 4 wire, and becomes a mess. You also generally use 2 wire when you are terminating to a mobile radio because it can only do one thing at a time. If it is transmitting, then it is not receiving, and when it's receiving, it is not transmitting. A 4 wire circuit would be pointless.

There are exceptions. As mention already by someone else, trunking systems must give users a go ahead tone after a ptt request. They do not necessarily get an immediate channel grant after pressing transmit. The user might get a busy, and if they are using a 2 wire circuit, they won't hear the busy tones, and will be talking to nothing forcing them to repeat their message to the field later after a successful channel grant. So, a 4 wire configuration is used to hear the beeps and boops returning from the mobile letting the user know whether to proceed or not.

4 wire is most commonly used in full blown, top level dispatch systems like in the public safety, transportation, and utility markets. The advantages of a full duplex system for safety and liability purposes are obvious. But, 4 wire can also be used in smaller, simpler systems that use remote controls like the MC2500 series so that the dispatcher can hear someone in the field calling in while they are speaking. Taxi companies are an example. Quite often they will have continuous duty base stations with a repeater split that are used as full duplex base stations, not as repeaters. The dispatcher will throw a rock on the transmit button and talk into the air non-stop for minutes at a time waiting for responses from cabbies in their headset. Private security and ambulance services are very similar. They will give out orders, and take check-ins at regular intervals during each shift with their foot on the transmit pedal for a long time. 4 wire isn't something a garbage service might want, but it is available to them.

Thus endeth the sermon. Now, if you will all turn to page 116 in the hymnal , we shall sing ....

[Jim202]

Before this goes over the edge and we get talking about the wrong piece of equipment, I would suggest that you find out just which J box your dealing with. the new ones that I have had to work with allow direct control of
radios like a consolette. The remote can display the radio channel in the alpha numeric form that is programmed
into the channel name. You can change channels, change zones, put the radio into scan and all that good stuff.
The cable interface between remote and the J box is via a standard cable like a CAT5 and uses RJ45 connections.
Not all the wires are used for all functions.

I just bought both a J box and a remote from MOL parts without a problem. Your price will depend on your
account discount.

Jim

[Bill_G]

Good point Jim.

So, the new MC2500 series with the DDN6337 offers enhanced features over local control when connected to the appropriate base? I did not know that. Very cool. That approaches the functionality of some of the trunking remotes I've seen on Astro consolettes.

[d119]

Those enhanced features are referred to as "Digital Control" and are offered on the MC 3000 desksets. It's completely and totally different from Local, Tone or DC control.

[Bill_G]

Ah. Thanks. So many cool products, and I've never seen some of them.

[Jim202]

Ah. Thanks. So many cool products, and I've never seen some of them.

The remote I have been playing with is the MC3000 part number L3223A and the J-box is part number L3208A.

Like I said earlier, you can buy both directly from MOL parts.

Control of the radio will depend on what is programmed, but the XTL5000 used in the consolette base has
the ability to have most of the functions available from the remote console including encryption control. As
in earlier versions, you can have a total length run of cable between remote and radio up to 1000 feet.
You can have up to 10 remotes on line with the use of multiple J-boxes. Use standard CAT5 cable and the B
wiring connections.

scan, monitor, channel (mode), zone, power level, ID display, etc.


Jim

[pluto1914]

Where I am only going to have one MC1000 in the building I guess I won't need the J Box.

It will be connected to an XTL5000 high power. Assuming I want to use the 25 pin connector on the transeiver what pins would I need to use?

David