Emerson Rosemount OCX 8800 - Page 8

7.6 Transducer block ........................................................................................................................113
7.6.1 Transducer block parameters ...................................................................................... 114
7.7 Transducer block enumerations ................................................................................................. 122
7.7.1 Calibration states .........................................................................................................122
7.7.2 Calibration step command .......................................................................................... 123
7.7.3 Transducer block channel assignments for AI blocks ....................................................128
7.7.4 Transducer block channel status ..................................................................................128
7.7.5 Transducer block simulate ...........................................................................................129
7.7.6 Support transducer block errors .................................................................................. 129
7.8 Analog input (AI) function block .................................................................................................130
7.8.1 Introduction ................................................................................................................ 130
7.8.2 Simulation ................................................................................................................... 135
7.8.3 Filtering ....................................................................................................................... 138
7.8.4 Signal conversion .........................................................................................................138
7.8.5 Direct signal conversion ...............................................................................................138
7.8.6 Indirect signal conversion ............................................................................................ 139
7.8.7 Indirect square root ..................................................................................................... 139
7.8.8 Block errors ................................................................................................................. 139
7.8.9 Modes ......................................................................................................................... 140
7.8.10 Alarm detection ...........................................................................................................140
7.8.11 Status handling ............................................................................................................141
7.8.12 Advanced features .......................................................................................................142
7.8.13 Application information ...............................................................................................142
7.8.14 Application examples .................................................................................................. 143
7.8.15 Pressure transmitter used to measure level in an open tank .........................................143
7.8.16 Differential pressure transmitter to measure flow ........................................................147
7.8.17 Troubleshooting ..........................................................................................................147
7.9 Proportional/integral/derivative (PID) function block ................................................................. 149
7.9.1 Setpoint selection and limiting .................................................................................... 158
7.9.2 PID equation structures ............................................................................................... 160
7.9.3 Reverse and direct action .............................................................................................161
7.9.4 Reset limiting .............................................................................................................. 161
7.9.5 Block errors ................................................................................................................. 161
7.9.6 Modes ......................................................................................................................... 162
7.9.7 Alarm detection ...........................................................................................................162
7.9.8 Status handling ............................................................................................................163
7.9.9 Application information ...............................................................................................164
7.9.10 Application examples .................................................................................................. 165
7.9.11 Cascade control with master and slave loops ............................................................... 167
7.9.12 Cascade control with override ..................................................................................... 169
7.9.13 Troubleshooting ..........................................................................................................170
7.10 Airthmetic (ARTHM) function block ............................................................................................172
7.10.1 Block errors ................................................................................................................. 175
7.10.2 Modes ......................................................................................................................... 176
7.10.3 Alarm detection ...........................................................................................................176
7.10.4 Block execution ........................................................................................................... 177
7.10.5 Compensation input calculations ................................................................................ 177
7.10.6 Application information ...............................................................................................178
7.11 Advanced topics .........................................................................................................................179
7.11.1 Arithmetic types ..........................................................................................................179
7.11.2 Troubleshooting ..........................................................................................................180
Contents
iv OCX 8800