Laurel Electronics LTA DPM SERIES ANALOG INPUT - Manual (Page 16)

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8. OPENING YOUR TRANSMITTER CASE
WHEN TO CHANGE JUMPERS
Most users will never have to open the transmitter case. The transmitters are shipped fully
jumpered and ready for scaling via Instrument Setup software. The factory configuration is
specified by the model number on the transmitter label.
Jumpers on the signal board set the signal range. To move jumpers, you will need to open the
transmitter. Your selected range should encompass your maximum expected signal levels. All
ranges are factory calibrated, with calibration factors stored in EPROM on the signal board.
Jumpers on the main board are used to select the data signal type (RS232, half duplex RS485,
or full duplex RS485), excitation level (5, 10 or 24V), and a possible RS485 line termination
resistor. Default factory jumpers are RS232 or RS485 (same jumpers), 10V excitation, and no
RS485 line termination resistor.
After changing jumper settings, you will need to update your data in Instrument Setup
software and on the transmitter label. While this software can sense the transmitter and signal
conditioner type, it cannot sense jumper settings which modify the electrical circuit.
HOW TO OPEN & CLOSE THE CASE
The two clamshell halves of the case are held together with 4 bolts and 4 nuts. When removing
these, take care to ensure that they are not lost. Separate the case halves. When closing the
case, make sure the ventilation grills are properly aligned.