PROTEUS
OMNTEC
Mfg., Inc., 2420 Pond Road, Ronkonkoma, NY 11779
Phone (631) 981-2001 Fax (631) 981-2007 www.OMNTEC.com
File Name: DE00014 DE00015 DE00020-10 rev2045.docx Page 6 of 71 Rev Date: 10-15-2021
Serial Interface Manual
OEL8000III Series Models K/X
4.1 COMPUTER FORMAT
The computer format is a stream of numbers without any formatting characters; i.e., carriage return, line feed,
spaces, labels, etc. The message format is as follows:
SOH | Format Char | Command Code | Data Field | 9 | Checksum | ETX (TLS-250 compatible)
SOH | Format Char | Command Code | Data Field | && | Checksum | ETX
(TLS-350 compatible)
The
SOH
is a Control-A character (ASCII 01). Start of string.
The
Format Character
(I, i, S, s, t) determines the type of command and response. A upper-case format character
will return a response in display format. A lower-case format character will return a response in computer format.
“I, i, t” = information response. “S, s” = set command.
The
Command Code
is identical to the received command message function code.
The
Data Field
contains the response message which is described in subsequent sections.
The
"&&"
or “
9
” is a fixed tag character which indicates that the checksum immediately follows.
The
Checksum
is a series of four ASCII-hexadecimal characters which provide a check on the integrity of all the
characters preceding it, including the control characters. The four characters represent a 16-bit binary count which
is the 2's complemented sum of the 8-bit binary representation of the message characters after the parity bit (if
enabled) has been cleared.
The data integrity check can be done by converting the four checksum characters to the 16-bit binary number and
adding the 8-bit binary representation of the message characters to it. The binary result should be zero. (see section
9.0)
The
ETX
end of string character is programmable. The default ETX character is a Control-C character (ASCII 03).
Caution should be taken before changing the ETX character, because it affects the transmitted messages on ALL
communications ports of the system, and additional host devices may be connected to other ports which expect the
ETX to be a Control-C.
4.2 DISPLAY FORMAT
The display format is intended for display on a CRT. It includes all the necessary formatting characters such as
carriage returns, line feeds, nulls, spaces, labels, etc. to view the data
