[SIGFOX] How many bytes can I transmit in one message to my device? You can send up to 8 bytes per message to the device (downlink). Last Update: August 8, 2017 December 5, 2016 1348 SIGFOX Q&A Downlink , Sigfox , Transmit Related Knowledge Base Posts -[SIGFOX] What is SIGFOX?[SIGFOX] How do I manage the unique ID and Key?[SIGFOX] What is the advantage of using the Radiocrafts RC16xxxx-SIG module?