This document provides information for setting Datel Displays DMS-20 PC (Figure 1) that are used to indicate fuel levels in Heatec fuel tanks. It applies to vertical tanks up to 40 feet tall equipped with Siemens pressure transmitters Sitrans P, Series DSIII.

Displays purchased from Heatec are normally set at our factory and require no further setup. However, personnel at the hot mix plant can use these instructions to reset a display if it ever becomes necessary to do that.

You will need a signal simulator, such as a Fluke 787 Processmeter, capable of providing outputs from 4 to 20 mA. You will also need a small screwdriver, such as a jewelers No. 0. Here’s how to reset the display (See Figure 2):

1. Disconnect existing wires from the two terminals on the back of the display.
2. Set DIP switches 3 and 6 to ON. Set all others to OFF.
3. Connect wires from the signal simulator to the two terminals on the back of the display (observe polarity).
4. Set the output of the simulator to 4.0 mA.
5. Adjust potentiometer R3 on the back of the display to make the display indicate 00.0.
6. Reset the output of the simulator to 20.0 mA.
7. Adjust potentiometer R7 on the back of the display to make the display indicate 40.0.
8. Reset the simulator to 4.0 mA and then to 20 mA to make sure the display still indicates 0 and 40. If not repeat the process.
9. Disconnect the wires from the simulator and reconnect the original wires.

The display should now indicate levels in feet above the point where the transmitter is installed. Thus, for transmitters installed 16 inches above the bottom of the tank, the display should indicate zero when the fuel is the same level as the sensor.

Please refer to Heatec Tec-Note, Publication 5-04-115 for more information on levels and the Siemens pressure transmitter.