The original network analysis tool was the National Instruments Bus Monitor, developed at approximately the same time as Foundation Fieldbus was being introduced. This tool was designed to monitor the data traffic on fieldbus networks. It was not until Relcom introduced the FBT-3 that a physical layer troubleshooting tool specific for Fieldbus was available. Prior to the FBT-3 the only options were multimeter and oscilloscope, with no way of knowing which devices were communicating when a signal trace went by.