Service manual

METTLER TOLEDO
DIVA Service Manual 34
6.1.1 NCI – ECR
6.1.1.1 OVERVIEW
The serial communications protocol is used to interface Weigh-Tronix/NCI POS (Point-of-Sale)
scales to ECR (Electronic Cash Registers), or other computing equipment (eg. personal
computers).
Baud rate and parity will be configurable. Start and stop bits will
each be fixed at one (1). Data bits will be fixed at seven.
Baud rates supported will be 1200, 2400, 4800, 9600 and 19200.
Responses to serial commands will be immediate, or within one weight meter cycle of the scale.
One second should be more than adequate for use as a time-out value by the remote (controlling)
device.
There are two types of serial commands: mandatory and optional. Mandatory commands must
be supported by all products.
If weight is negative, in motion, over capacity or under capacity, or if a zero error exists, only the
scale's status is returned in response to a weight ('W') command.
Status bytes are prefaced by the letter 'S'
Units of measure abbreviations are always upper case.
The weight is always positive, therefore there is no polarity byte
Key to symbols used:
<ETX> End of TeXt character (03 hexadecimal).
<LF> Line Feed character (0A hex).
<CR> Carriage Return character (0D hex).
<SP> Space (20 hex).
x Weight characters from display including minus sign and out-of range
characters.
hh Two status bytes.
UU Units of measure (LB, KG, OZ, G, etc., all upper case).
Mandatory Commands
Name: Request weight
Command: W<CR>
Response: Returns decimal weight, units and status. (see note 1 and 2)
<LF>xx.xxxUU<CR><LF>Shhhh<CR><ETX>
Returns lb-oz weight with units plus scale status.
<LF>xLB<SP>xx.xOZ<CR><LF>Shhhh<CR><ETX>
Scale status only if wt < 0, initial zero error, in motion or out of capacity.
<LF>Shhhh<CR><ETX>
Name: Request status
Command: S<CR>
Response: Returns scale status.
<LF>Shhhh<CR><ETX>