Communicating via wireless connection has become commonplace in the 21st century. Cell phones, laptops, PDAs and other electronics constantly remind us of this trend. As this capability has become more widespread, so has the desire to enjoy the benefits of wireless communications in traditionally wired applications. In this application note, you will see several examples showing the benefits of accessing Sealevel SeaI/O RS-232 data acquisition modules via a Bluetooth wireless connection.
Bluetooth is an open specification for seamless wireless short-range communications to establish a Personal Area Network, or “PAN”, between electronic devices. Sealevel offers a Bluetooth serial adapter (Item # BT-SD100) that interfaces to SeaI/O RS-232 data acquisition modules to allow wireless communication with any Bluetooth enabled host up to 100 meters away. An included RJ45 to DB9 cable connects the SeaI/O device with the RS-232 to Bluetooth adapter and supplies the required 5V power. Using the Sealevel universal mounting plate (Item # KT125), the Bluetooth adapter is easily mounted to the SeaI/O module using a plastic or Velcro tie wrap as shown below.
Image 1: Sealevel SeaI/O RS-232 module with Bluetooth adapter mounted to universal mounting bracket (Item# KT125)
For applications where it’s not convenient to mount the Bluetooth serial adapter to the SeaI/O module, standard DB9 RS-232 serial extension cables can be used to extend the Bluetooth adapter further away from the SeaI/O module. Since SeaI/O RS-232 modules provide power through the cable. Extra cables and bulky power supplies are not needed to power the Bluetooth serial adapter.
Image 2: Sealevel SeaI/O module with remote mounted Bluetooth adapter
Once connected to the Bluetooth adapter, the SeaI/O module is easily accessed via any Bluetooth enabled host as shown in the following examples:
Bluetooth Enabled PDA Host:
A Bluetooth enabled PDA running a mobile supervisory monitoring and control program communicates with a Bluetooth enabled SeaI/O module. SeaI/O modules are a convenient way to expand your supervisory control system with optically isolated inputs, Reed and Form C relay outputs, and TTL interfaces to industry standard relay racks.
Image 3: A Bluetooth enabled PDA allows mobile supervisory monitoring and control of a Bluetooth enabled SeaI/O module
Bluetooth Enabled Laptop Host:
A Bluetooth enabled laptop running a third-party monitoring and control program interfaces two separate Bluetooth enabled SeaI/O RS232 modules. Each SeaI/O module operates as a separate slave device. Up to seven Bluetooth enabled slave devices can communicate concurrently with the host laptop.
Image 4: A laptop running third-party monitoring and control program accesses data from different SeaI/O modules via Bluetooth
Bluetooth Enabled HMI Host:
A Bluetooth enabled host HMI system is used to interface to a network of SeaI/O modules. The Bluetooth serial adapter adds a wireless Bluetooth connection to the first SeaI/O RS232 module. Up to 246 additional SeaI/O expansion modules can be added to the network via convenient RS-485 pass-through connectors on the SeaI/O module. This overcomes the traditional point-to-point limitation of RS-232 and the seven device limitation of Bluetooth.
Image 5: Host HMI system allows wireless monitoring of SeaI/O module and control of I/O via touchscreen input
Existing monitoring and control programs that use a wired RS-232 serial port will work using a wireless Bluetooth connection. Applications where Bluetooth performs well include serial cable replacement, wireless factory monitoring, control system diagnostics, and wireless vehicle monitoring, just to name a few. Call us at 864.843.4343 to discuss your specific application requirements