Bailey infi 90 IMASI03 Instruction

Contents

Bailey infi 90 IMASI03 Instruction Manual pdf 41 page image

CONFIGURATION AND CALIBRATIONCALIBRATING INPUTS4 - 2 15 December 1994 I-E96-301B1®slave module connected to an analog input signal. The type ofthe input, as well as the zero and span in engineering units,must also be specified to ensure proper scaling and correctionsfor field calibration, cold junction compensation or nonlinearitycorrection. Function code specifications also contain the A/Dresolution, lead wire resistance (if such a correction is desired),and primary frequency of the noise to be rejected by eachinput.For cold junction compensation, the block which representsthe cold junction input must also be specified. To use theslave’s on board cold junction reference, set specification 3 infunction code 215 to the block address of function code 215.Any channel can be used as a remote cold junction reference(in function code 216 specification 4, enter 1xx).When an input channel is selected as a remote cold junctionreference, software smoothing of the input reading takes place.This smoothing allows the temperature response of the remotecold junction reference to closely match the temperatureresponse of the remote terminal blocks.Each slave configured for a thermocouple input requires a coldjunction reference. Each slave can only have one cold junctionreference for up to 16 thermocouple inputs. The exception tothis is when one of the thermocouple inputs is used as aremote cold junction reference.Install one function code 217 block in the MFP configuration incase slave tuning or field calibration operations are neededlater.CALIBRATING INPUTSCalibration is done at the factory and the calibration data isstored on the slave in nonvolatile memory. No calibration isnecessary. If, however, field calibration is desired, use the pro-cedure described in the field calibration instructions.Field calibrate the IMASI03 slave with the MFP by tuning func-tion code 217 which is described in Appendix C. It is necessaryto install function code 215 and one function code 216 for eachinput channel in a configuration to field calibrate a slave. Inaddition, when field calibrating a slave, the calibration typedefined in S4 of function code 217 must be consistent with theinput signal type defined in S4 of function code 216. Considerthe following examples.Example 1 If calibrating a channel for millivolts or thermocouples, then S4of function code 217 must be set to zero and S4 of functioncode 216 must be set to any one of the millivolt or