ASP ClassNet, Руководство пользователя

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ClassNet Terminal User Manual 17
Technical Specifications
Barcode:
Decodes Code 39 barcodes of up to 30 characters in length. Barcode
scanning is bi-directional A fixed barcode length can be set.
IDTag Decodes the 16-character tag ID.
Display
Four digit 6mm high seven segment display.
Clock The time is displayed and stored in 12 hour format. The clock is
battery-backed to maintain the time and date in the absence of power.
Each barcode and IDTag stored in memory is time and date stamped.
Storage
Memory Approx. 30,000 characters are available for data storage. Storage
memory is battery-backed to maintain the data when power is off.
To calculate the amount of data that can be stored between
downloads, divide the amount of storage memory (ie 30,000) by the
length of the barcode or IDTag number, plus an overhead 8 bytes for
barcodes, or 7 bytes for IDTags. The overhead consists of 6 bytes for
the time and date, plus one byte to indicate the length of the scan, and
one byte for the direction indicator (only for barcodes).
For example, with 8 character barcodes, 1875 scans would fit in
memory (ie 30000 / (8 + 8) = 1875), while 1304 IDTags would fit (ie
30000 / (16 + 7) = 1304).
Network
Up to 31 ClassNet Terminals can be attached to a single RS-485
network, with up to 1200 metres of cable. Network ID numbers can
be set from 01 to 98.
Communications are at 9600 baud, using 8 data bits, no parity and 1
stop bit, using an RS-485 interface.
To maintain compatibility with the previous model of the ClassNet
Terminal, downloading is performed approximately 2000 bytes at a
time. If more than this amount of data is stored in memory, the
remaining data is retained until the next download.
The first and last units on the RS-485 network must be terminated
using the jumper included on each unit. The first unit in an RS-485
network is usually the Intelligent Converter.
DataTag
Download
DataTags hold approximately 8000 bytes of data. If a DataTag
download is commenced and there is more than this amount of data is
stored in the memory of the ClassNet Terminal, the DataTag will be
filled, the display will show
LOAD
and the DataTag must be returned
to the PC for data retrieval. The remainder of the data stored in the
ClassNet Terminal’s is retained until the next download.