This document is the SIM900 Multiplexing User Manual, which describes the features and characteristics of the SIM900 product.
The document is an application note for the SIM900 GSM/GPRS module, offering general notes and technical background for engineers integrating the product. It clarifies that system validation remains the customer's responsibility and that specifications may change.
It includes definitions of DLC commands, multiplexing protocol details, AT command sets, timer values, flow‑control commands, and contact information for SIMCom support. The note serves as a reference for implementing and troubleshooting the module in larger systems.
| Acknowledgement Timer (T1) | 100 ms |
|---|---|
| Response Timer (T2) | 300 ms |
| Wake‑up Response Timer (T3) | 10 s |
| Maximum Frame Size (N1) | 255 |
DLC stands for Data Link Connection.
The command is called FCon, which stands for Flow Control On Command.
You can reach SIMCom at Tel: +86 21 3235 3300 or visit www.sim.com/wm.