Transmission Speed Setting in CM Board

5 Minute read

| Overview

The 75F BMS (Building Management System) uses several sensors to sense various parameters in the building these sensors communicate the sensed information to different types of smart devices which can be a SmartNode, HelioNode, Smart stat, and HyperStat. The sensors are usually wired to smart devices.

The smart devices collect the information from the sensors and sense certain other parameters themselves.

All of this information is aggregated in the CCU the communication happens via the Bluetooth connectivity with which the smart devices are paired to the CCU.

The aggregated information in turn is communicated to the BMS applications (Facilisight and Internal portals) for viewing by the facility manager. The communication is facilitated by the CM via the 900 MHz mesh network where the CCU tablet is mounted.

Transmission speed is an option that is made available in the CM (Control Mote) and the smart devices for the user to decide on the type of transmission speed which is the speed at which all the data that is aggregated is transmitted to the BMS applications.

| Transmission Speed

The transmission speeds used in the 75F system are of two types and are set in both the CM (Control Mote)

Note: The Transmission speed type set in the CM (Control Mote) should always match with the transmission speed type set in the smart devices for proper communication.

Low Transmission Speed:

The 'Low' transmission speed is the default mode where the transmission happens via the digital modulation technique BPSK Modulation, and the data is transmitted at a speed of 40 Kbit/ sec.

Medium Transmission Speed:

The 'Medium' transmission speed where the transmission happens via digital modulation technique QPSK Modulation and the data is transmitted at a speed of 250 Kbit/ sec. 

| Setting Transmission Speed in the CM

The Transmission speed type in the CM (Control Mote) is set using the two dip switches provided by the CM board.

Below are the steps to set the Transmission speed type in the CM board.

• Remove the CCU tablet from the CM board.

• Locate the Dip switches provided to set the transmission speed type.

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The Dip switches have two Positions “0” or “1” (Left is 0 /Right is 1. These two-minute white switches can be moved from left to right and right to left using a small pin screwdriver or fingernails. ​

By Default Mode, both the switches are on the left which is towards Position “0” and implies the CM is communicating in “Low” speed where the transmission happens via digital modulation technique BPSK Modulation, and the data is transmitted at a speed of 40 Kbit/ sec.

• Move both the switches to the right ​which is towards Position “1” to set the CM communication speed to “Medium" speed, where the transmission happens via digital modulation technique QPSK Modulation, and the data is transmitted at a speed of 250 Kbit/ sec.

Below is a table to illustrate the Dip switch positions and their corresponding descriptions, of what the positions of the Dip switches mean.