Hi, everybody This is a little off topic, I apologize! But I couldn't resist the oppurtunity to get some good advice from this excellent forum. We are about to design or procure a wireless field measurement system. Any ideas about the design in general or possible existing hardware would be appreciated. The system should consist of two or more synchronized A/D converter units and one controller unit. Distance between the units can be up to 200 m and it can be a rather bad EMC environment. Requirements: * Max 100 us between samples * Synchronized sampling within 1 us (not necessarily by hardware) * Max voltage 100V AC * Amplitude accuracy 0,02% - 0,05% I see two main ways in which the synchronization can be achieved - please add your own thoughts: 1) A radio signal of some kind either synchronizes the sample clocks of the two A/D converters or trigs the measurement. They must however start simultaneously within 1 us. 2) Another way that does not demand such high level of synchronism of the hardware, would be to have 2 channels per A/D unit and let the second channels sample a known, common, sinusoidal reference signal. That way, the data processing can use the reference channels to phase shift the signals so that they become synchronized. Further, I imagine some GPS device could do the job. By supplying either a sinusoidal reference signal or a trig pulse. Any thoughts and ideas are welcome! Does anyone perhaps know of a suitable hardware? Regards, Andreas Nilsson, SP Swedish National Testing and Research Institute mailto:[EMAIL PROTECTED]
