RockBLOCK 9704

No, RockBLOCK 9704 does not use the legacy AT command set used by older Iridium SBD devices.

The Iridium Certus 9704 transceiver uses JSPR, Iridium’s JSON-based serial protocol. You can work with JSPR directly if you want low level control, but most developers use our open source C and Python libraries instead. They handle the protocol layer so you can send and receive messages without learning JSPR first.

Select the patch antenna if your unit will have a clear view of the sky directly or sit beneath an RF-transparent plastic enclosure cap. Choose the SMA variant if the unit is buried deep inside a metallic chassis, which necessitates running a cable to an external antenna.

Yes. The board features a 3.3V TTL UART connection and a USB-C serial bridge running at a default speed of 230400 baud. It interacts via Iridium's JSON-Based Serial Protocol for REST (JSPR), which can be quickly integrated using our provided C, Python, and Arduino SDK libraries.

Airtime is purchased separately from the hardware.

When your IMT device arrives, register it online at the Cloudloop Console. You can buy message credits, manage your device, and start sending messages without speaking to sales.

If you prefer post-pay airtime, contact our team at hello@groundcontrol.com and we can switch your account over.

You can find PAYG and post-pay airtime rates at https://www.groundcontrol.com/products/iridium-messaging-transport-imt-pricing/.

No, RockBLOCK 9704 does not include its own GNSS receiver.

It does support GNSS passthrough via a U.FL connector, so the Iridium antenna path can be shared with a separate GNSS receiver in your design. Your host system still needs to provide and manage the GNSS receiver.

RockBLOCK 9704 is a good fit for remote monitoring, industrial sensors, autonomous systems, ocean and field science equipment, off-grid telemetry, mobile assets, gateway devices, backup command links, and applications that need to send more than a few hundred bytes from outside terrestrial coverage.

If your device needs to report useful batches of data, not just a status flag, 9704 is probably the RockBLOCK to look at first.

Yes. Like all satellite devices, antenna placement matters. The patch antenna option is suitable when the module can "see" the sky, including through some non-metallic enclosures. If the module will sit deeper inside an enclosure, or behind metal, use the SMA variant with a suitable external antenna.

In ideal conditions, an already powered device can complete an Iridium IMT message session in around 10 seconds. That assumes a clear view of the sky, good antenna placement, and a successful session on the first attempt.

We wouldn't recommend designing your application around guaranteed 10 second reporting. In real installations, buildings, terrain, vehicle bodywork, ship structures, trees, antenna placement, RF interference, and satellite movement can all affect how quickly a session completes. Larger messages will also take longer to transmit than very small payloads.

For most applications, it's better to design around retries and occasional delays. Send when you have data to report, retry quickly if the first attempt fails, then back off to a longer retry interval if needed. IMT is well suited to larger telemetry packets, batched sensor data, logs, configuration files, and other message-based payloads, but it should not be treated as a fixed-interval real time link.

As a rule of thumb: around 10 seconds is a best case session time for small messages, not a guaranteed reporting interval.