3
DPI-500
Technical Manual
The DPI-500 is a multipurpose indicator, which is NTEP approved at 5000 divisions. This indica-
tor is housed in stainless steel and meets all NEMA 4X standards. The large 0.75" display is easy
to see from a distance and is capable of showing up to 50,000 divisions. The DPI-500 also sup-
plies enough current to drive eight 350
Ω
load cells.
All system and user keyword parameters can be changed through the front panel, including calibra-
tion.
The DPI-500 has two RS-232C communication modes: full duplex and Gross/Net/Tare. Place the
indicator in full duplex mode for communicating with a computer or a remote display. The unit can
transmit on demand or continuously. Place the indicator in Gross/Net/Tare mode for connecting
directly to a printer.
A crude layout of the DPI-500 circuit board is shown in
Figure 1
. This layout shows the major compo-
nents, as well as the input and output terminal blocks. The inputs and outputs consist of a load cell
terminal (J8), DC power supply terminal (J1), and a serial communications terminal (J3).
Figure 1: CPU Board Layout
E+ S+ E- S- SH
P+ P- TXD RXD GND +5
J4
J6
JP2
J8
J1
J3
CPU
EPROM
Installation and Wiring
