Condec DLR334 - Manual (Page 3)

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DLR334 PRESSURE DUPLEX SERIAL PROTOCOL
1.0 GENERAL:
! This document applies to the basic Pressure program KDG-1.
! The duplex protocol includes the following basic functions:
♦ Setup entry and recall.
♦ Current pressure data recall.
♦ Calibration and correction recall and entry.
♦ All front panel key functions.
♦ Temperature calibration and correction recall and entry.
! The protocol between the “standard” full duplex and the RS485 will only differ by the addition of
the origin and destination address characters.
! The protocol will be designed to be expandable for future growth and special applications.
2.0 FULL DUPLEX PROTOCOL:
Communications from the host computer into the DLR:
*
Response from the DLR:
:
Where:
“<”,”>” Brackets are not sent
* = Message from master (host computer)(2AH).
: = Response from DLR (3AH).
DD = DLR unit address (two digit) if in RS485.
OO = Master address (fixed at 00) if in RS485.
If RS485 mode not selected the “DD” and “OO” are not transmitted.
Cmd = Three character command to DLR.
Cmd r = Three character command echoed from DLR.
{
= Start of data character (7BH).
} = End of data character (7DH).
‘{‘ and ‘}’ only sent if data entry or recall.
Data entry= Data entered into DLR if entry command.
Data resp = Data response from DLR if in response.
CHECK
= Optional two character check if selected.
CR = Message terminator (0DH).
A “LF” character following the “CR” will be ignored. All characters following
the “CR” and preceding the “*” will be ignored.
3.0 COMMAND CODE DESCRIPTION:
The consists of three (3) characters “ppt” where:
pp = the command parameter.
T = the command type.
The three (3) command types (t) are as follows:
Direct cmd code = < D > character (44H).
‘D’ Commands have no data associated with them.