Loadstar Sensors DI-1000U Digital Load Cell Interface Manual - Manual (Page 13)

DI-1000 Di1000 User Guide
Page: 13 / 25
P/N : 033-01591 Rev. 6
The DI-1000 connects signal ground to the adapter power ground, and also connects to the USB
signal power ground. Ideally this ground should be connected to any cable shield, but not the load
cell body. Many load cell assemblies connect the cable shield to the load cell body. This creates a
problem, since any ground connection between the load cell and your system ground will induce a
current in this combined ground system. In this case, you’ll need to connect the load cell shield to
the DI-1000 earth ground terminal, so a ground loop is not formed with the load cell within your
system. Make sure your earth ground is electrically clean, to avoid introducing excessive common
mode noise into your load cell signal wiring.
The DI-1000 earth ground is isolated from signal ground, which is connected to the USB host
shield ground. Keep in mind that EMI performance and ESD protection depend on the earth
ground connection, so this shield terminal should ALWAYS be connected to a suitable earth
ground in your system. That connection in some cases may be adequately made by the USB
cable itself to your PC. It is your responsibility to verify this is the case.
The simplest approach is to simply connect all system grounds to the DI-1000 earth ground
terminals. If performance isn’t adequate in this case, then experimenting with system grounding,
can often improve system performance.
2.4 Install Virtual COM port drivers
The DI-1000 may be accessed on your host PC using either using a simple virtual COM port
mechanism, or by using the LoadVUE application. For information on LoadVUE, please refer to
the manual which ships with that software CD for more details.
This document will focus on the virtual serial interface. This approach may be easily adapted to
user programs, and is very flexible.
Please install the drivers for the DI-1000 using the included iLoad Digital USB Driver disc or, if you
have purchased LoadVUE software, from the LoadVUE disc. Instructions are included with the
documentation that comes with your driver disc or LoadVUE.
Once you have connected the DI-1000U physically to your PC, you can use the steps outlined in
the document entitled
“Driver Installation and Hyperterminal Operation of iLoad Digital USB
Sensors and Interface Devices ” to determine the COM port assigned and to connect to
HyperTerminal.
Please note that the instructions in the booklet above are written primarily for Loadstar Sensors’
iLoad series of Digital USB sensors, but will work with the DI-1000 as well with the one change that
the Baud rate for communication should be set at 9600 (or 230400 for DI-1000U-HS high speed
models)..
2.5 Connect the USB Host (e.g., your PC) to the DI-1000
2.6 Terminal command line operation
Once you are connected to the DI-1000 via HyperTerminal or another terminal emulator, press
<ENTER> several times. You should get an “A” returned onscreen for every <ENTER> pressed.
You may now type ASCII commands to the DI-1000, to remotely monitor and control the attached
sensors.
You may press “?” at any time to see the available command list. The available commands will be
described in detail in the next chapter.
2.7 Initial set up of the DI-1000
1. Enter desired units: UNIT LB← (← stands for the Enter key)
2. Enter total load capacity of the attached load cell (e.g., 100 lb): LC 100.0 ←
3. Enter your desired load cell name: ID SENSOR_1