User manual

Computer Remote Control
ProMaster 2500 User Manual E-11
Hex Label Format
The Hex Label format has been developed to encode data files in ASCII
format to transfer between the Remote RS232C port on the 2500 and the
attached computer system.
Label Record
Content
Label records appear as character strings consisting of the following four
fields: identifying record type, record length, data, and checksum. Each
byte of binary data is encoded as a 2-character hexadecimal number; the
first character represents the four high-order bits, and the second
represents the four low-order bits of the byte. The four fields are
described below.
Each record can be terminated with a CR/LF/NULL. Accuracy of
transmission is ensured by the record length (byte count) and checksum
fields.
Label Record Types
Eight types of label records facilitate information exchange between the
2500 and other computer systems. Two more have been identified for
future requirements. These records are described below.
Q0
The header record for each block of label records. The data field can
contain any descriptive information identifying the following block of
label records.
Q1
A record containing labeling information. The data field may contain up
to 8 lines of 18 characters specifying the contents of the label. A 0D hex is
used as a delimiter between lines. A copyright character can be selected
by a 1F hex.
Field
No. of ASCII
Characters Description
Record Type 2 Label Record Type Q0, Q1...Q9.
Record Length 2 The count of the character pairs
in the record, excluding the
record type and record length.
Data 0-2
n
From 0 to
n
bytes of data.
Checksum 2 The least significant byte of the
one’s complement of the sum of
the values, represented by the
pairs of characters making up the
record length and the data fields.