MPL Radio Detail

Read one MPL position closely — its alias, its squelch types, and the tones behind them.

An MPL position is small but dense: one alias with a receive, a transmit, and a direct setting behind it, each with its own squelch type and its own tone or code. This page walks through one position line by line so you can be sure which tone the radio will actually use, and where the rest of a position's programming shows up elsewhere in the app.

Overview

Each position is shown as a single block of labeled lines in the MPL list. The lines printed on screen are these five:

Line	What it means
n. Alias	The position number, then the alias the radio shows for it
RX Type	The squelch type used when receiving
TX Type	The squelch type used when transmitting
RX FREQ	The receive tone frequency
Direct FREQ	The tone frequency used in direct/talkaround operation

Behind those lines, each position carries a fuller set of values, and these are the ones that surface on a channel's Squelch block when the operator selects this position:

Direction	Values a position holds
Receive	Squelch type, tone frequency, tone code, digital code, digital invert
Transmit	Squelch type, tone frequency, tone code, digital code, digital invert
Direct / talkaround	Squelch type, tone frequency, tone code, digital code, digital invert

note

There is no separate screen for one position. Tapping a row in the MPL list does nothing — everything about a position is already on its row, and the values not printed there appear in a channel's details once the position is in use.

Getting Here

1. From the Home screen, open References.
2. Select Communications.
3. Choose a codeplug on the Radio Info screen.
4. Tap MPL Config to open the position list.
5. Find the position you want by its number or alias and read its five lines.

Reading the Squelch Types

The type is the most important value on the row, because it decides whether a tone frequency matters at all.

Type family	What the radio does	Does the tone frequency matter?
Carrier squelch	Opens on any signal on the frequency	No — any tone shown is not used
Tone squelch (PL)	Opens only on the programmed tone	Yes — the frequency shown is required
Digital squelch (DPL)	Opens only on the programmed digital code	The code matters, not a frequency
Network access code	Opens only for the programmed network code	The code matters, not a frequency

1. Read RX Type first — this governs what you will hear.
2. Read TX Type next — this governs what the other end needs to hear you.
3. Read Direct FREQ if you will be working unit to unit without a repeater.

caution

Receive and transmit are programmed separately and do not have to match. A position can receive on carrier squelch while transmitting a tone, which means you will hear everything on the channel but only tone-equipped radios will hear you.

Reading the Tone Frequencies

1. RX FREQ is the tone that has to be present for your radio to open.
2. Direct FREQ is the tone used in direct/talkaround, which is often different from the repeater tone.
3. A blank frequency means the codeplug carries no tone for that direction in this position — check the type line to see whether one was ever needed.

What you see	What it usually means
A frequency on both RX FREQ and Direct FREQ	Normal tone-squelch position, with a separate talkaround tone
A frequency on RX FREQ only	No separate direct tone is programmed
No frequency, carrier squelch type	The position deliberately uses no tone
No frequency, tone squelch type	The codeplug is incomplete for that position — verify before relying on it

tip

Write down the position number and the receive tone before a mutual aid assignment. On the radio you only see the alias, so the number and tone from this screen are what let you confirm you are on the right position.

Location and Distance Lines

Some MPL positions are tied to a site rather than to the whole system, and where a codeplug carries site information the row can show a location line alongside the tone values, and a distance from your current position measured in miles.

What you see	What it means
A location and a distance in miles	The position's site is known and your device has a position, so the distance is measured between them
Location not provided	No usable coordinates are stored for that position, so no distance can be worked out
No location line at all	The codeplug carries no site information for MPL positions

note

Distance figures depend on your device knowing where it is. If location access is switched off, or your position has not been established yet, expect Location not provided rather than a distance.

Cross-Checking Against a Channel

The point of a position is what it does to a channel, so read the two together.

1. Note the position number and alias here.
2. Open the channel in question from Channels.
3. Look at the channel's Squelch block.

What the channel shows	What it means for this position
User-selectable (MPL)	The channel uses whichever position the operator selects — including this one
RX: User-selectable (MPL)	Only receive is selectable; transmit uses the channel's own fixed tone
TX: User-selectable (MPL)	Only transmit is selectable; receive is fixed
A fixed tone with no MPL note	The channel ignores this list entirely

Loading, Empty, and Error States

State	What you see
Loading	A loading indicator while the positions are fetched or read
No positions	An empty list — no MPL positions in this codeplug
Blank values on a row	The codeplug carries no value for that line
Request failed	An alert with the message returned by the server
Codeplug not downloaded, no connection	"This codeplug isn't available offline."

How This Connects

• Where a position comes from. Positions belong to the codeplug you opened on Radio Info and are listed in MPL Radio List. With a connection they are fetched for that codeplug; offline they are read from the downloaded copy on your device.
• Why the extra values are hidden. The row prints the five lines that matter for choosing a position. The codes and invert settings behind them are applied by the radio and appear in a channel's Squelch block in Zone & Channel Details, where the display is filtered to the active squelch type.
• What makes a channel selectable. The gating rule — which channels offer these positions at all — is explained in MPL Configuration.
• Location depends on GPS. Any distance shown uses your device's current position, the same source as GPS View, and needs location permission — see Permissions.
• Used with incidents. When a comms plan specifies a tone, confirm the position number, the receive tone, and the transmit tone here before you key up — see Incident Comms Tab.
• Offline and reconnect. Position values read fully offline for downloaded codeplugs. Distances need your device position, which works offline too; only the codeplug itself needs to have been downloaded.

Troubleshooting

If this happens	What to do
Tapping a position does nothing	Correct — there is no deeper screen. Everything is on the row.
Location not provided instead of a distance	No coordinates are stored for that position, or your device has no position. Check location permission.
A tone frequency is blank on a tone-squelch position	The codeplug is incomplete for that position. Verify with whoever programs the radios before relying on it.
Receive and transmit tones differ	That is allowed and often deliberate. Read both lines before you transmit.
You cannot tell which position the radio is on	The radio shows the alias; match that alias to a row here to get the position number.
The channel shows a fixed tone, not MPL	That channel does not use these positions at all.
The aliases mean nothing to you	Aliases come from the codeplug and vary by agency. Use the position number and the tone values instead.
"This codeplug isn't available offline."	Open this codeplug once while connected so it downloads.

Related Pages

• MPL Radio List
• MPL Configuration
• Zone & Channel Details
• Channels

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