This manual provides an overview of the CH-M1 series wireless modem, describing its features, supported frequency bands, and intended use cases. It also includes version history, reference documents, and a glossary of technical terms.
Safety warnings, liability limitations, contact information, and a detailed FAQ are included to help users install, configure, and troubleshoot the device safely and effectively. This manual is written in Chinese.
| Supported frequency bands (GPRS model) | 900 MHz (EGSM) / 1800 MHz (DCS) |
|---|---|
| Supported frequency band (CDMA model) | 800 MHz |
| Baud rate setting | 19200 bps |
| Maximum SMS length (English) | 140 characters |
| Maximum SMS length (Chinese) | 70 characters |
| Typical SMS sending rate | ≈750 messages per hour per modem |
A single SMS can contain up to 140 English letters or 70 Chinese characters, including spaces and punctuation.
In normal network conditions, a CH-M1 modem can send about 750 SMS messages per hour.
No, a CDMA SIM card cannot be used in a GPRS modem; you need a CDMA modem.