1.0GENERAL INFORMATION
Model TX82B two-wire current-loop indicator accepts 1-5 mA, 4-20 mA, or 10-50 mA process signals and digitally displays the process variable in percentage or engineering units of such measurements as pressure, flow, temperature and level. No separate power supply or power connections are required, since the TX82B obtains operating power directly from the current loop with a voltage drop of less than 2.5 V. It can tolerate current overdrives up to 200 mA forward and 1000 mA reverse.
The compact TX82B circuit is mounted in a black polycarbonate case with the standard 1/8 DIN panel-mount bezel and a depth of less than 110 mm (4.33 in). Five 12.7 mm (0.5 in) high liquid crystal 7-segment digits are used to display ±1999 active counts plus one or two dummy right-hand zeros.
The TX82B displays from -1999 to 1999 counts with the option of one or two dummy right-hand “0” digits. Zero suppression or elevation capability exceeds full scale. Program jumpers are used to scale the readout for percentage or engineering-unit display. Both zero and span are fine-tuned with multiturn potentiometers accessible through the display board, requiring lens removal for readjustment.
When removed from its case, the TX82B can be programmed with gas-tight jumpers for three input ranges (1-5, 4-20 or 10-50 mA), four coarse zero ranges, four decimal-point locations and the dummy right-hand zeros. Two additional jumpers are provided to reverse the span slope so that increasing the input can cause a reading decrease; thus a 4-20 mA input can be programmed to produce a 2000 to -18000 reading when one dummy right-hand zero is also used.
