FIELD TRANSMITTER FOR STORING INFORMATION

摘要

A transmitter (22) in a process control loop (34) includes a sensor (40) for sensing a process variable. An analog-to-digital converter (42, 44) coupled to the sensor (40) provides a digitized process variable at various sample times. An interface (54) couples the transmitter to the control loop (34) and is used for communicating information and receiving power over the control loop (34). The transmitter (22) includes a clock (52) and a memory (50). A microprocessor (48) coupled to the clock (52) and the memory (50) stores digitized process variables and clock information in the memory (50). The storage is such that the sample time of a stored digitized process variable can be determined.