During standard operation of Measurand ShapeArrays, a communication baud rate of 38,400 bps is desired. Our SAARecorder software supports communication rates beyond this threshold for cases where higher frequency readings are desired and the communication infrastructure (e.g. cabling and power) is capable of supporting these higher rates. For this reason, the Complete Diagnostics test in SAARecorder will typically try to test a variety of baud rates to give you an indication of your system’s capabilities.
In some cases, the higher baud rates are not tested by SAARecorder. This is because in these instances, the higher communication rates are unlikely to be possible due to the hardware or technology being used. These cases include the following:
- Communication through a wireless Bluetooth connection
- Communication through an SAA232-5 interface
- Communication with very long model 3 SAAF instruments
In the case of wireless communication, in our experience, job sites where ShapeArrays are typically used have many sources of interference that reduce the quality of wireless communication. For this reason, we limit the baud rate at which the wireless communication occurs to ensure proper operation.
In the case of communication through a Measurand SAA232-5 interface, the nature of how this device switches communication channels does not lend itself to higher communication rates.
And finally, in the case of very long model 3 SAAF instruments, the hardware design of the instruments does not lend itself to the higher communication rates. The design of longer SAAFs consists of separate groupings of segments each controlled by a separate piece of special hardware known as an SAATop. The way these instruments work is by powering up and querying each section independently of the other. Due to the switching nature of this communication, higher baud rates are not possible and are therefore not tested.
NOTE: This behaviour/limitation does not exist in our most recent SAAX and SAAV designs as these instruments do not require multiple SAATops to accommodate the longer instruments.