Problems

· The first problem we encountered was finding a transceiver that met the requirements and specifications. We found many transceivers but very few that had all the features we wanted such as error checking and at least 4 channels.

· We had difficulty interfacing transceiver with serial port. The transceiver uses 0 to 5 volt logic and the serial port uses -15 to 15 volts. We found a line driver manufactured by Maxim that did all the voltage conversations for us and only used a 5 volt supply.

· The Labview software we designed initially couldn’t read or write to the serial port in hexadecimal. The transceiver accepts only hexadecimal commands when it is in programming mode. By default Labview communicates in ASCI a simple conversion was needed to format the serial data.

· We first tried to manufacturer our own printed circuit boards. This was more difficult than we initially realized, spacing is critical as well as a good photo resist. We ended up with boards that only had about 30% of the connections being solid. We decided that getting the boards made professionally was a better because it was within our budget.

· The initial delays we were seeing for sending to and from transceivers was 50ms one way. We read through the documentation and found that if the baud rate was not programmed into the transceivers this could cause substantial delays.

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