AnyTone AT-D168UV · D868UV · D878UV · D890UV · D578UV

How Digital Monitor Works

v1.05

What the setting filters, how to aim it at one timeslot or both, how to answer someone it lets you hear, and what changes when you add a second radio or a second hotspot.

First: not every radio has this

Start here

Digital Monitor is not part of the DMR standard. Nothing in the protocol requires a radio to offer it, and many DMR radios do not. Programming cannot add the feature to a radio whose firmware lacks it.

Check your radio against the list below before reading further. If it is not there, skip to the RX group list comparison, which is the closest thing you can build yourself.

Radio or firmware What to look for
AnyTone Present across the current line: AT-D168UV, AT-D868UV, AT-D878UV and AT-D878UVII Plus, AT-D890UV, and the AT-D578UV mobile. Listed as Digi Moni in the radio menu and Digital Monitor in the CPS. Early AT-D868UV manuals do not document it; the shipping firmware has it.
Same platform BTECH DMR-6X2, 6X2 Pro and DA-7X2; Alinco DJ-MD5. Built on the same platform, with the same four settings and the same menu.
OpenGD77 Set the DMR filter to None. Its timeslot filter works differently from AnyTone's Double Slot: the firmware listens on both slots until valid data appears on one, then follows that slot. Runs on the Radioddity GD-77 and GD-77S; TYT MD-UV380, MD-9600 and MD2017; Retevis RT-3S, RT-84, RT-90 and RT-82; and Baofeng DM-1801, DM-1801A, DM-1701 and RD-5R.
MD380tools Promiscuous mode on the TYT MD-380 and MD-390, via third-party firmware.
Motorola · Hytera Generally not offered as a user menu item. Some Hytera PD6xx and PD7xx models reach something similar through a developer-mode OVCM receive option, and only for transmissions carrying that flag.
Other DMR radios Many DMR radios have no equivalent setting on stock firmware. The RX group list is then your only tool.

The rest of this page uses AnyTone menu names, since that is where the feature is most commonly met. The behavior described applies to any radio offering promiscuous monitoring, whatever its own firmware calls it.

Two filters sit between the network and your ears

Every DMR transmission carries a label saying which talkgroup it belongs to and which timeslot it rides on. Two separate things decide whether you hear it, and Digital Monitor only touches one of them.

Network thousands of TGs filter 1 Hotspot your static TGs six, in this example RF Radio RX group list filter 2 You Digital Monitor nothing gets past here that you did not link
Digital Monitor bypasses the radio's RX group list only. The hotspot's filter stays in place, so the setting can never surface a talkgroup your hotspot was not already carrying.
What the setting reaches

Digital Monitor does not open you up to the whole network. You hear your static talkgroups and nothing else. If your hotspot has six talkgroups linked, six is the ceiling. The setting only stops your radio from narrowing those six down to one.

Off, Single Slot, Double Slot

These examples assume a duplex hotspot

A duplex hotspot carries both timeslots, so talkgroups can sit on TS1 and TS2 at the same time. A simplex hotspot carries one slot, and Pi-Star puts everything on TS2. On a simplex hotspot there is no TS1 traffic to hear, Double Slot has nothing extra to unmute, and Case 2 below is not available.

Everything on this page also applies to a DMR repeater, which carries both slots the same way a duplex hotspot does.

The examples below use a duplex hotspot with three static talkgroups on each slot, and a radio sitting on a channel programmed for TG31068 on TS1. They also assume DigiMoni Id is set to Any Id, which is the part that drops the talkgroup filter. With Same Id, the Switch alone changes nothing about which talkgroups you hear.

DigiMoni Switch — Off
1 talkgroup heard
TS1 — your slot
31068 31075 31064
TS2
3106 31078 31067

Only the talkgroup your channel names. The other five arrive at the radio and are discarded.

DigiMoni Switch — Single Slot
3 talkgroups heard
TS1 — your slot
31068 31075 31064
TS2
3106 31078 31067

Everything on the slot your channel uses. TS2 stays shut.

DigiMoni Switch — Double Slot
6 talkgroups heard
TS1
31068 31075 31064
TS2
3106 31078 31067

Both slots, every static talkgroup. Still one call at a time.

Choosing TS1, TS2, or both

There is no TS1 / TS2 selector

The menu offers Off, Single Slot, and Double Slot. Nothing in it names a slot. Single Slot follows whichever slot your current channel is programmed for, so you pick the slot by picking the channel, not by changing this setting.

To monitor Do this
TS1 only Select a channel programmed for TS1, then set the DigiMoni Switch to Single Slot.
TS2 only Select a channel programmed for TS2, then set the DigiMoni Switch to Single Slot. Same setting, because the channel does the choosing.
Both slots Set the DigiMoni Switch to Double Slot. The channel's slot no longer matters for listening.

The setting lives at Menu → Digi Moni on the radio, or under Optional Settings in the CPS. Digital Monitor is radio-wide, not part of a channel and not part of a zone. Turn it on and it stays on across every channel and zone until you turn it off, which is why it is worth assigning to a programmable key.

Setting What it does
DigiMoni Switch Off · Single Slot (the current slot) · Double Slot (TS1 and TS2).
DigiMoni Cc Same Cc hears only your color code. Any Cc hears any color code on the frequency, which matters on a repeater pair shared with another system.
DigiMoni Id Same Id keeps the talkgroup filter. Any Id drops it. Any Id is the part that makes this promiscuous mode.
Slot Hold Holds the radio on the slot it is decoding for a few seconds when the signal drops, instead of switching to the other slot immediately. Without it, a momentary dropout can move you to activity on the other slot part-way through a transmission. The manual recommends turning it on when monitoring both slots.

Answering someone Digital Monitor let you hear

Hearing a conversation does not move you to it. Your channel still points at its own talkgroup, so plain PTT sends you there rather than to the call you were listening to. Read the display first, then use one of three routes back.

01

Read the display first. While the call is coming in, the radio shows the talkgroup the traffic belongs to, and the caller's callsign when a digital contact database or talker alias supplies it. That number is what you need, and it clears once the call ends, so look while it is on screen.

02

Monitor Response, while the call is still up. The AnyTone firmware has a response function built into Digital Monitor for exactly this. During a call whose ID does not match your channel, press the response key and the screen shows Monitor Response Setup Successfully; PTT then answers that call. The same menu can save the heard talkgroup into a zone as a new channel. The manual does not name the key in its text, and third-party guides report it as *, so confirm it on your own radio.

03

Reply by Manual Dial. Press and hold the 0 key to jump to the Input ID screen, or take the full path at Menu → Talkgroup → Manual Dial. Enter # followed by the talkgroup number for a group call, then key up. The # prefix is what separates a group call from a private call, and leaving it off sends a private call to that number instead.

04

Reply by switching channels. If the talkgroup is one you use often, select the channel already programmed for it. Slower in the moment, but the display shows the talkgroup's programmed name and the channel's own RX group list still applies.

Watch the slot

Manual Dial changes the talkgroup, not the timeslot. If you heard the call on the other slot through Double Slot monitoring, dialing the number still transmits on your channel's slot, and the people you are answering never hear you. Move to a channel on the correct slot first.

Three levers at three points in the chain

Digital Monitor is one of three ways to end up hearing more talkgroups, and each pulls at a different point in the chain.

Lever Lives at Changes
Static TGs the network which talkgroups your hotspot pulls down at all
RX group list the channel, in your codeplug which of those arriving talkgroups the radio unmutes for
Digital Monitor the radio, globally switches the RX group list off entirely

Against an RX group list holding many talkgroups

A long RX group list reaches a similar result by a different mechanism. The differences are set out below.

RX group list Digital Monitor
Scope One channel. Other channels are unaffected. The whole radio, every zone, until switched off.
Selectivity You name each talkgroup. Anything not listed stays muted. All or nothing. No way to admit five talkgroups and exclude a sixth.
Timeslots The channel's slot only. A channel has one slot, so a list cannot reach the other. Double Slot crosses to the other slot, which no RX group list can do.
Changing it Edit the codeplug and reprogram the radio. A menu toggle, or one press of a programmable key.
Upkeep Goes stale. Add a static talkgroup at BrandMeister and the list needs updating to match. None. It admits whatever turns up.

Use an RX group list when you know which talkgroups you want and expect to live with the choice. Reach for Digital Monitor when you do not know yet, when you want the other slot, or when you are exploring an unfamiliar repeater. The list is set up once and then maintained; the monitor is a single toggle.

TGIF talkgroup 777

TG 777 is often raised alongside Digital Monitor, and it is not an alternative to it. It works at the opposite end of the chain. On TGIF, linking 777 is reported to make the server send you every active talkgroup on the network rather than only your subscriptions, which widens filter 1 — the one Digital Monitor cannot touch.

The two need each other. Traffic arriving that way still carries its own original talkgroup ID rather than 777, so a channel whose RX group list does not name that talkgroup stays muted. Two ways round it: turn Digital Monitor on, or populate the RX group list with the talkgroups you want. Forum discussion favours the first for the simple reason that you cannot list what you have not met yet.

Verify this one before relying on it

The behaviour of TG 777 described above comes from TGIF user forum threads, the earliest from 2018. It is not confirmed in TGIF's current help site, and the network's own talkgroup list carries 777 under an ordinary talkgroup name. Confirm the present behaviour with the network before relying on it.

The concept holds regardless: a network-side monitor talkgroup fills the pipe, and a radio-side setting opens the gate. Networks handle talkgroup delivery differently, so check the current documentation for whichever one you are on.

Where Digital Monitor makes the most difference

On a hotspot you configured yourself, the setting reveals only what you already chose to link. On a repeater you do not control, it reveals things you had no way of knowing about.

Picture a repeater whose owner has three talkgroups statically linked to TS1: a statewide group, a regional group, and a TAC channel. Your channel is programmed for the statewide group. Two operators are mid-conversation on the regional group, on that same slot.

With Digital Monitor off, the radio stays silent. The slot is busy, but nothing at the radio shows it, so a transmission started then lands on top of the conversation already running. With Single Slot on, that conversation is audible, and the choice to wait or to join is yours to make.

Why Single Slot is the everyday setting

Single Slot is the setting to reach for first, and it works as a courtesy feature as much as a listening one. Knowing the slot is occupied before you transmit matters more day to day than hearing the other slot.

What changes with more radios and more hotspots

Digital Monitor filters talkgroups and slots. It does not tune frequencies. That single fact decides all four cases below.

Case 1

One radio, one hotspot

Radio TS1 / TG31068 one frequency pair 6 static TGs available Hotspot TS1 ×3 · TS2 ×3
The ordinary setup. Digital Monitor moves you along the scale from one talkgroup to three to six, and six is the hard ceiling the hotspot sets.
Result Digital Monitor does real work here. Single Slot gives you the other two talkgroups on your slot; Double Slot gives you all six. To hear more than six, link more talkgroups at the network, because the radio setting cannot do it for you.

Case 2

Two radios, one hotspot

Radio A TS1 ch · Single Slot Radio B TS2 ch · Single Slot same frequency pair Hotspot TS1 + TS2 live
Both radios sit on the same frequency pair. Each one decodes its own slot from the same downlink carrier, which is the only way to get two conversations in the room at once.
Result The setup that does what Double Slot cannot. A single radio on Double Slot follows one call and misses the other when both slots go active together; two radios, each on Single Slot on its own slot channel, genuinely deliver both. Give both radios the same frequencies and color code, change only the slot, keep them on low power, and keep the two talkgroups different so you do not hear yourself returned.

Case 3

One radio, two hotspots

Radio tuned to A heard wrong frequency — never heard Hotspot A 421.0125 Hotspot B 438.8000
Two hotspots mean two frequency pairs. One radio sits on one of them, and Digital Monitor has no say in which.
Result Digital Monitor adds nothing across hotspots. Hotspot B is on a frequency your radio is not listening to, and no talkgroup filter can fix that. The tool for this job is a scan list holding both hotspot channels, and scanning has its own limit, since it stops on the first active channel and stays there while the other hotspot goes unheard.

Case 4

Two radios, two hotspots

Radio A Double Slot Radio B Single Slot Hotspot A 421.0125 Hotspot B 438.8000 two independent paths, both live
Each radio holds its own Digital Monitor setting, because the setting belongs to the radio rather than to a channel.
Result The widest coverage of the four. Radio A can run Double Slot while Radio B runs Single Slot or Off, and the two never interact. Keep both radios on low power and separate the two hotspots in frequency; close spacing on one bench can degrade reception on either.

What Digital Monitor cannot do

Four limits worth stating plainly.

It does not decrypt. Encrypted traffic stays unintelligible. Promiscuous mode removes an address filter, not a cipher.

Range and sensitivity are untouched. Nothing about the receiver changes. A signal too weak to decode stays too weak to decode.

It does not tune frequencies. Whatever is not arriving at your antenna on the frequency you are sitting on stays out of reach. That is scanning territory.

Nothing is fetched from the network. The hotspot pulls down what you linked, and no radio setting reaches back up the chain to change that.

Five details worth knowing

01

The setting is radio-wide. Not per channel, not per zone. Switch zones and it is still on. Assign it to a programmable key so turning it off takes one press instead of four menu levels.

02

PTT ignores what you just heard. Listening to 31075 through Digital Monitor does not move you there. Key up and you transmit to the talkgroup your channel names. Use Manual Dial or switch channels first, as above.

03

Double Slot is not two audio streams. The radio has one receiver and decodes one call at a time. If both slots go active at once, you get one of them. Two radios are the only real answer to that.

04

Any Cc can admit other systems. On a hotspot this usually changes nothing, since nothing else is normally using that frequency within range of you. On a shared repeater pair it can bring in a completely different system running the same frequency with another color code.

05

A lightly loaded hotspot has nothing to reveal. One static talkgroup per slot means Digital Monitor has nothing to unmute. The setting earns its keep when several talkgroups share a slot, or on a repeater whose linking you do not control.

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