ATM Communications

S4 IP Controller

For simple, direct access to a radio voice channel in ATM, the S4 IP Controller puts you in complete control of your communication system with an intuitive user interface.

Where simple, direct access to a radio voice channel in safety critical ATC environments is necessary, the S4 IP Controller is the answer. 

Compliant with the latest VoIP standards for ATC, the S4 IP Controller is perfect for use in airport, dispatch or last resort applications. A full range of channel configuration and main/standby features are included to suit a wide range of scenarios.

Designed to work as an integral part of your network, S4 IP Controller supports multiple connections to one or many radios. They put you in complete control of your communications system with a simple and intuitive user interface.

The S4 IP Controller has various mounting choices and a software-only PC application for complete flexibility.

Features & Benefits

Flexible connectivity.

Seamless connection with radios and ‘monitor and control’ equipment. The S4 IP Controller integrates seamlessly with all T6 and M7 radios, as well as the R4 MARC Server for monitoring the device status. They will also operate with any ED-137 compliant radio.

Control for one radio or many more.

A single S4 IP Controller can be connected directly to one T6 radio channel or each S4 IP Controller can be connected to up to eight radio channels at a time for complex situations. With main and standby transmitters and receivers, this allows up to 32 T6 radios to be controlled from a single S4 IP Controller.

Automatic or manual changeover.

Main/standby radios can be set to either automatic or manual changeover. The S4 IP Controller will allow the channel frequency to be changed from a single action, thus ensuring all radios comprising a channel are updated simultaneously.

Built for future networking standards.

The S4 IP Controller conforms to all editions of EUROCAE ED-137 for VoIP interoperability and performance via two independently addressable IP ports. Facilities include audio access and monitoring, radio configuration, status monitoring, main/standby operation and role-based configuration.

USB connection.

A USB connector enables software and configuration files to be transferred to and from the device.

Dual power inputs.

Power is provided by dual 12V DC inputs for main and standby power sources.

Two headset sockets, plus footswitch and loudspeaker sockets. Two front panel mounted self-locking sockets allow for two independent ATC headsets to be connected to the S4 IP Controller. This allows the radio channel to be simultaneously monitored or controlled by a supervisor or trainer. An external PTT footswitch can be connected to the unit and an integrated loudspeaker is also provided.

Intuitive interface.

Multiple-function touchscreen display. The S4 IP Controller’s 8″ display enables configuration of up to 8 radio channels, with controls for Rx, Tx, squelch override and PTT priority level. Controls for brightness and volume are also easily available from the main screen.

Multiple-channel operation.

The interface allows receive channels to be selected simultaneously. This means that operators can monitor multiple channels, allowing reduced staffing during quieter periods. Additionally, operators can control key radio parameters such as transmitter power and receiver squelch threshold. A Go/NoGo link status to each channel is also clearly displayed.


Safe and secure operation is enhanced through role-based security. Users can log in with a user-defined role and defined permissions. Roles are set up typically by an operations manager, each role being configured to make specific channels and controller capabilities available. The ability to save and recall configuration settings to file simplifies configuration of multiple units via the USB port.

S4 IP Controller Specifications

Maximum channels per screen



8" TFT LCD colour touchscreen with 800x600 resolution


204 mm (H) x 294 mm (W) x 48 mm (D)

Network standards

ED-137 (all editions)