Radio Programming

DMR radios operate in a channelised mode and behave differently to normal analogue 2m and 70cm rigs. Clean programming removes most operating problems before they happen. If the colour code, slot, talkgroup or DMR ID is wrong, the network cannot help you.

Channelised operation

A few DMR radios can be programmed directly from the front panel, but most are programmed from a computer. A DMR channel is not just a frequency. It normally includes frequency, colour code, timeslot, talkgroup contact, power level, admit criteria and a display name.

Codeplugs

The programming files for DMR radios are known as codeplugs. They are computer files containing the parameters to be programmed into the radio, and each radio family normally uses its own CPS programming software.

Start simple

Writing your own codeplug can be challenging, but once the basic concepts are clear, any amateur with basic computer skills can do it. A small, clean codeplug is usually better than a large one full of channels you do not understand.

Using someone else’s codeplug

Using a codeplug from another radio is not recommended as a direct write to your radio. It can create firmware or model compatibility problems, and you could inadvertently transmit using someone else’s DMR ID.

For a starting point, ask on the VK DMR Network [OFFICIAL] Facebook group for someone with the same radio to send a basic codeplug. Open it in the CPS, study the structure, then modify it to suit your needs. The first thing to change is your own DMR ID in the general settings.

Slots and talkgroups

DMR uses Time Division Multiple Access to provide two 30 ms timeslots in one 12.5 kHz radio channel. Each timeslot can carry an independent voice conversation, so a DMR repeater provides two simultaneous voice paths.

Timeslot 1
Dynamic and wide-area talkgroups

Timeslot 2
Local and network call channels

Talkgroup contacts

Each timeslot has talkgroups that work like discrete channels within that slot. Users on one talkgroup will not hear users on another. The talkgroups you want to use must be programmed into the radio and then assigned to channels for each repeater or hotspot.

DMR ID

Every DMR user has a 7 digit ID number from radioid.net. Your DMR ID must be programmed into the radio because it is sent with every transmission. VK IDs begin with 505.

User database and digital contacts

If you download all or part of the worldwide DMR ID database into your radio, the radio can look up received DMR IDs and display the user’s name and callsign. This database is often called the digital contacts list.

Database capacity varies between radios. Some hold only around 1000 contacts, while some newer radios can store hundreds of thousands of IDs and may hold the full worldwide callsign database.

Programming workflow

Connect the programming lead to the radio and read the radio first.
Program your DMR ID in the settings or general menu.
Add the talkgroup contacts you will use. See the live Talkgroups page.
Create channels for each repeater, hotspot and talkgroup combination.
Group related channels into zones, normally one zone per repeater or operating area.
Write the codeplug back to the radio and test each channel.

Minimum channel setup

Colour code: always 1 on VKDMR.
Timeslot: 1 or 2, depending on the talkgroup.
Repeater RX and TX frequencies.
Power output, high or low as appropriate.
Talkgroup contact.
Channel name or alias, normally repeater name and talkgroup.
Your own DMR ID programmed correctly.

Repeating channels and zones

Each repeater has a number of logical channels, each using a separate talkgroup and timeslot. Repeat the channel setup for each talkgroup you need. Usually only the channel name, talkgroup and timeslot change; the repeater TX and RX frequencies stay the same.

Most CPS software uses the commercial term zone for a group of channels. If you use more than one repeater, put each repeater in its own zone so the radio is easy to operate.

Radio parameters

Button functions, display backlighting, scan lists and audio settings can also be programmed from the CPS. Once the radio is working, customise these items carefully and keep a known-good backup copy of the codeplug.

Radios with GPS

Many DMR radios can transmit GPS position data. Do not enable in-band GPS position reporting unless you have been specifically advised that your radio and service are configured for VKDMR GPS use. Incorrect GPS settings can create unwanted network traffic.

Hotspot notes

Simplex hotspots only have one effective talkpath.
Duplex hotspots present two independent timeslots.
If something sounds wrong, check whether the hotspot is in scan mode or listen-only/block mode.

Check your programming

A good way to check that channels are programmed correctly is to watch the live dashboards as you key each channel briefly. The dashboard will show whether the correct talkgroup and timeslot are being used.

Repeater dashboard for repeater activity.
Hotspot dashboard for hotspot registration, RX, TX and talkgroup state.
Parrot to check your transmitted audio level and timing.

Further resources

VK DMR Network [OFFICIAL] Facebook group for help from other users.
RadioID.net for DMR ID registration and database lookup.
Radio-specific CPS and programming videos on YouTube.
Vendor documentation for your exact radio model and firmware version.
Community resources such as GD77, OpenGD77 and other model-specific guides where applicable.