The 6B13 and 6B13HV are single-channel isolated signal-conditioning modules which accept outputs from platinum, nickel and copper RTD sensors. Unlike conventional signal conditioners, the 6B13 and 6B13HV are complete microcomputer-based data acquisition systems. A major advantage of the on-board microcontroller is its ability to be remotely reconfigured for various sensor types and input ranges.
The 6B13 and 6B13HV linearize 100 Ω platinum RTDs (alphas of 0.00385 and 0.003916), 120 Ω nickel RTDs and 10 Ω copper RTDs. Software is used to configure the 6B13 and 6B13HV modules for address, input range, baud rate, data format, checksum status and integration time. All programmable parameters are stored in the nonvolatile memory of the module.
Inside the 6B13 and 6B13HV
RTD sensor excitation current of 250 µA (2.25 mA for copper RTDs) is supplied by a tracking pair of current sources.The resulting analog input signal is conditioned and scaled by a programmable-gain amplifier and digitized by a 16-bit integrating converter under microprocessor control. The digitized value is passed serially across a magnetically isolated barrier (1500 V rms - Model 6B13; 2500 V rms - Model 6B13HV) and clocked in by a custom controller chip. The on-board microprocessor then converts the data into engineering units or as a percentage of full scale, as determined by the channel parameters. In between conversions, the microprocessor auto zeros the offset and gain by monitoring the on-board temperature and compensating for reference drift. The 6B13 and 6B13HV use compensation factors to ensure the highest accuracy possible.
Inputs and Communications
Figure 1. 6B13/6B13HV Functional Block Diagram
Figure 2. 6B13 and 6B13HV Field Connection Diagram