Cross modem modes

The openSPOT2 supports the following cross modes:

• You can use your DMR transceiver to access C4FM and NXDN networks
• You can use your C4FM transceiver to access DMR, NXDN and P25 networks
• You can use your NXDN transceiver to access DMR and C4FM networks
• You can use your P25 transceiver to access C4FM networks

Note that cross mode using a D-STAR transceiver/network is not supported, as D-STAR uses an older, incompatible voice codec, and it requires built-in audio transcoding hardware, which only the openSPOT3 has.

Using a DMR connector with a C4FM radio

After you've activated the DMR connector, switch the modem to C4FM mode (or C4FM Half Deviation mode, if your radio needs that). Only calls in DN (Digital Narrow) mode will be converted, if you transmit in other modes, DMR users will only hear silence.

The source DMR ID of your calls from the C4FM radio will be set to the ID associated with the source callsign. If there's no ID associated, then the source callsign will be parsed into a number and this will be used as the source DMR ID. If it can't be parsed into a number, then the Default cross mode source DMR ID will be used. You can set this to your DMR ID.

The callsign of incoming DMR calls will be set to the callsign associated with the DMR ID. If there's no callsign associated in the database, then the Default callsign for cross mode calls will be used. If it's not set, the callsign will be the source DMR ID as text.

Keep in mind that the audio gain used by DMR and C4FM transceivers differ, and correcting this would require audio transcoding hardware which the OS2 does not have, so the audio coming from the network may sound distorted on your C4FM transceiver.

Using a DMR connector with an NXDN radio

After you've activated the DMR connector, switch the modem to NXDN mode.

The source DMR ID of your NXDN calls will be set to the same value as the NXDN call unless the Always use this ID in cross mode setting is enabled for the Default cross mode source ID on the Settings page, NXDN settings section.

Your NXDN calls will be sent to the same DMR ID as the NXDN call's destination ID unless the Always use this ID in cross mode setting is enabled for the Default cross mode destination ID on the Settings page, NXDN settings section.

The destination and source NXDN IDs for an incoming DMR call will be set to the same value as the incoming call's destination and source ID unless the Always use this ID in cross mode setting is enabled for the destination/source NXDN IDs on the Settings page, NXDN settings section (or if the incoming DMR call's destination or source ID is out of the NXDN ID range (0-65535)).

Private DMR calls are converted to NXDN group calls.

Using a C4FM connector with a DMR radio

After you've activated the C4FM connector, switch the modem to DMR mode. Only calls in DN (Digital Narrow) mode will be converted to your DMR radio, if someone transmits in other modes on the C4FM network, you will hear silence on your DMR radio.

Your outgoing callsign will be the callsign associated with the DMR source ID. If there's no callsign associated to the ID, then the callsign will be the Default callsign for cross mode calls. If this is not set, your outgoing callsign will be your radio's DMR ID as text.

An incoming call's source DMR ID will be set to the ID associated with the source callsign. If there's no ID associated, and the source callsign can be parsed into a number, it will be used as the source DMR ID. Otherwise the Default cross mode source DMR ID will be used.

All calls coming from the C4FM network will be sent as a group call to DMR ID 9 (TG9). Make sure TG9 is the TX contact of your DMR radio's current channel, or it's in an RX group list which is assigned to the current channel in the radio, otherwise the squelch won't open and you won't hear the calls.

Keep in mind that the audio gain used by DMR and C4FM transceivers differ, and correcting this would require audio transcoding hardware which the OS2 does not have, so the audio coming from the network may sound quiet on your DMR transceiver.

Using a C4FM connector with an NXDN radio

After you've activated the C4FM connector, switch the modem to NXDN mode. Only calls in DN (Digital Narrow) mode will be converted to your NXDN radio, if someone transmits in other modes on the C4FM network, you will hear silence on your NXDN radio.

Your outgoing callsign will be the callsign associated with the NXDN source ID. If there's no callsign associated to the ID, then the callsign will be the Default callsign for cross mode calls. If this is not set, your outgoing callsign will be your radio's NXDN ID as text.

An incoming call's source NXDN ID will be set to the ID associated with the source callsign. If there's no ID associated, and the source callsign can be parsed into a number, it will be used as the source NXDN ID. Otherwise the Default cross mode source ID will be used.

All calls coming from the C4FM network will be sent as a group call to the Default cross mode destination ID. If you don't hear calls on your radio then make sure this ID is in the selective call list (or SelCall is turned off), or it's the TX contact of the current channel.

Keep in mind that the audio gain used by NXDN and C4FM transceivers differ, and correcting this would require audio transcoding hardware which the OS2 does not have, so the audio coming from the network may sound quiet on your DMR transceiver.

Using a C4FM connector with a P25 radio

After you've activated the C4FM connector, switch the modem to P25 mode. Only calls in VW (Voice Wide) mode will be converted to your P25 radio, if someone transmits in other modes on the C4FM network, you will hear silence on your P25 radio.

Your outgoing callsign will be the callsign associated with the P25 source ID. If there's no callsign associated to the ID, then the callsign will be the Default callsign for cross mode calls. If this is not set, your outgoing callsign will be your radio's P25 ID as text.

An incoming call's source P25 ID will be set to the ID associated with the source callsign. If there's no ID associated, and the source callsign can be parsed into a number, it will be used as the source P25 ID. Otherwise the Default cross mode source P25 ID will be used.

All calls coming from the C4FM network will be sent as a group call to P25 ID 9 (TG9). Make sure TG9 is in the selective call list of your P25 radio's current channel, or SelCall is turned off, or TG9 is set as the TX contact for the current channel, otherwise the squelch won't open and you won't hear the calls.

Using an NXDN connector with a DMR radio

After you've activated the NXDN connector, switch the modem to DMR mode.

The source NXDN ID of your DMR calls will be set to the same value as the DMR call unless the Always use this ID in cross mode setting is enabled for the Default cross mode source ID on the Settings page, NXDN settings section.

Your DMR calls will be sent to the same NXDN ID as the DMR call's destination ID unless the Always use this ID in cross mode setting is enabled for the Default cross mode destination ID on the Settings page, NXDN settings section, or the destination DMR ID is out of the NXDN ID range (0-65535). In this case, the Default cross mode destination ID will be used for the NXDN call.

The destination and source DMR IDs for an incoming NXDN call will be set to the same value as the incoming call's destination and source ID unless the Always use this ID in cross mode setting is enabled for the destination/source NXDN IDs on the Settings page, NXDN settings section.

Make sure the destination ID of the NXDN calls (the NXDN talkgroup) is the TX contact of your DMR radio's current channel, or it's in an RX group list which is assigned to the current channel in the radio, otherwise the squelch won't open and you won't hear the calls.

Using an NXDN connector with a C4FM radio

After you've activated the NXDN connector, switch the modem to C4FM mode (or C4FM Half Deviation mode, if your radio needs that). Only calls in DN (Digital Narrow) mode will be converted, if you transmit in other modes, NXDN users will only hear silence.

All C4FM calls will be sent to the Default cross mode destination ID on the NXDN network.

The source NXDN ID of your calls from the C4FM radio will be set to the ID associated with the source callsign. If there's no ID associated, then the source callsign will be parsed into a number and this will be used as the source NXDN ID. If it can't be parsed into a number, then the [Default cross mode source ID] will be used. The default ID will be used if the Always use this ID in cross mode setting is enabled for the Default cross mode source ID on the Settings page, NXDN settings section.

The callsign of incoming NXDN calls will be set to the callsign associated with the NXDN ID. If there's no callsign associated in the database, then the Default callsign for cross mode calls will be used. If it's not set, the callsign will be the source NXDN ID as text.

Keep in mind that the audio gain used by NXDN and C4FM transceivers differ, and correcting this would require audio transcoding hardware which the OS2 does not have, so the audio coming from the network may sound distorted on your C4FM transceiver.

Using a P25 connector with a C4FM radio

After you've activated the P25 connector, switch the modem to C4FM mode (or C4FM Half Deviation mode, if your radio needs that). Only calls in VW (Voice Wide) mode will be converted, if you transmit in other modes, P25 users will only hear silence.

The source P25 ID of your calls from the C4FM radio will be set to the ID associated with the source callsign. If there's no ID associated, then the source callsign will be parsed into a number and this will be used as the source P25 ID. If it can't be parsed into a number, then the Default cross mode source P25 ID will be used. You can set this to your DMR/P25/CCS7 ID.

The callsign of incoming P25 calls will be set to the callsign associated with the P25 ID. If there's no callsign associated in the database, then the Default callsign for cross mode calls will be used. If it's not set, the callsign will be the source P25 ID as text.