User's Manual

NOMAD
™
- W4-2 SCALES
O
PERATING
I
NSTRUCTIONS
P
AGE
7 of
13
28-Oct-2001
3. USE OF TRANSPONDER TAGS
The scale may be used with contactless transponders. The transponders
themselves are credit card sized and derive their power from the radio signal
that interrogates them. The transponders are normally fixed to a harvesting
cart such that they pass the reader as the cart is loaded onto the weight
platform. An external “strobe” input would normally be derived from a volt
free contact pair in the controller of the grading machine.
The reader is housed in a separate enclosure and should be connected to
PL2 via a screened cable.
The strobe input should be connected to PL4.
3.1 OPERATION WITH TRANSPONDERS
When a transponder is in range of the reader and the controller is in
operator mode the transponder number will be displayed in large digits at
the bottom of the screen.
When a strobe input is applied to the controller to instruct it to take a
reading the last transponder number is used. The scale will wait until the
weight is stable before accepting the reading, but should the stability time
threshold be reached the reading will be accepted regardless.
3.1.1 TARE OF A TRANSPONDER CART
The tare for each cart or range of carts (identified by the transponder
number) can be set from the Nomad PC.
4. CHARGING
Connect the controller to the main supply. After a second has elapsed the
controller will beep and the message “CHG1” or “CHG2” will be displayed.
These messages indicate that the terminal is charging.
The charging cycle and the meaning of the “CHG” messages is as follows.